Non-monogamy#Terminology

In the Western world, from a legal perspective, marrying more than one person is not permitted, as the law recognises only monogamous marriage—a union between two individuals.{{Cite book |last=Witte |first=John Jr |title=The Western Case for Monogamy over Polygamy |date=2015 |publisher=Cambridge University Press |isbn=9781316182031}}{{Cite journal |last=Barker |first=Nicola |date=2018-11-13 |title=The Evolution of Marriage and Relationship Recognition in Western Jurisdictions |journal=UN Women Discussion Papers |doi=10.18356/1c046084-en |isbn=978-92-1-047602-7 |issn=2521-6112}} However, in many other regions, particularly Muslim-majority countries, polygamy is legally recognized and culturally normalized.{{Cite journal |last1=Purwanto |first1=Muhammad Roy |last2=Mukharrom |first2=Tamyiz |last3=Syibly |first3=M. Roem |last4=Nurozi |first4=Ahmad |date=2021 |title=Polygamy in Muslim Countries: A Comparative Study in Tunisia, Saudi Arabia, and Indonesia |journal=Advances in Economics, Business and Management Research |series=Proceedings of the 2nd Southeast Asian Academic Forum on Sustainable Development (SEA-AFSID 2018) |volume=168 |location=Paris, France |publisher=Atlantis Press |isbn=978-94-6239-347-9 |doi=10.2991/aebmr.k.210305.082|doi-access=free }} Another key characteristic that distinguishes different forms of nonmonogamous relationships is whether they are practiced with the knowledge and consent of all involved parties. These distinctions allow non-monogamy to be broadly categorised into three major forms:

• Culturally institutionalised non-monogamy refers to legally and culturally sanctioned practices of non-exclusive relationships that are formalised, regulated, and embedded within specific cultural traditions. The most prominent example is polygamy, which includes polygyny (when a man has more than one wife at the same time), and, less commonly, polyandry (when a woman has more than one husband), and polygynandry (a group marriage when more than one husband is married to more than one wife).{{Cite journal |last1=Al-Sharfi |first1=Mohammad |last2=Pfeffer |first2=Karen |last3=Miller |first3=Kirsty A. |title=The effects of polygamy on children and adolescents: A systematic review |journal=Journal of Family Studies |date=2016-09-01 |volume=22 |issue=3 |pages=272–286 |doi=10.1080/13229400.2015.1086405 |issn=1322-9400}}{{Cite book |last=Goodwin |first=Robin |title=Personal Relationships Across Cultures |date=2013-05-13 |publisher=Routledge |isbn=978-0-203-43416-1 |edition=1st |language=en |doi=10.4324/9780203434161}} Other culturally embedded practices, such as temporary marriages (e.g., Nikah Mut'ah in Shia Islam), may also fall under this category.{{cite book |last1=Hasannia |first1=Ali |chapter=Temporary Marriage Among Shiite and Sunni Muslims: Comparative Study of 'Istimtā', Mut'ah, and Misyār |date=2021 |title=Temporary and Child Marriages in Iran and Afghanistan |pages=31–45 |editor-last=Hosseini |editor-first=S. Behnaz |place=Singapore |publisher=Springer Singapore |language=en |doi=10.1007/978-981-33-4469-3_2 |isbn=978-981-334-468-6 |last2=Masoudian |first2=Mostafa}}  
• Consensual non-monogamy (CNM), also known as ethical non-monogamy (ENM), refers to a relationship that explicitly allows for extra-dyadic romantic or sexual relationships.{{Cite journal |last1=Conley |first1=Terri D. |last2=Ziegler |first2=Ali |last3=Moors |first3=Amy C. |last4=Matsick |first4=Jes L. |last5=Valentine |first5=Brandon |date=May 2013 |title=A Critical Examination of Popular Assumptions About the Benefits and Outcomes of Monogamous Relationships |journal=Personality and Social Psychology Review |language=en |volume=17 |issue=2 |pages=124–141 |doi=10.1177/1088868312467087 |pmid=23175520 |issn=1088-8683}}{{Cite journal |last1=Burleigh |first1=Tyler J. |last2=Rubel |first2=Alicia N. |last3=Meegan |first3=Daniel V. |date=2017-04-03 |title=Wanting 'the whole loaf': zero-sum thinking about love is associated with prejudice against consensual non-monogamists |journal=Psychology & Sexuality |language=en |volume=8 |issue=1–2 |pages=24–40 |doi=10.1080/19419899.2016.1269020 |issn=1941-9899}} Consensual non-monogamy can take many different forms, depending on the needs and preferences of the individuals involved in specific relationships. The most studied and prevalent forms of consensual non-monogamy are swinging, polyamory, and open relationships.{{Cite book |last1=Richards |first1=Christina |url=https://sk.sagepub.com/Books/sexuality-and-gender-for-mental-health-professionals |title=Sexuality and Gender for Mental Health Professionals: A Practical Guide |last2=Barker |first2=Meg |date=2013 |publisher=SAGE Publications Ltd |isbn=978-0-85702-843-3 |location=London |doi=10.4135/9781473957817}}{{Cite journal |last1=Rubel |first1=Alicia N. |last2=Bogaert |first2=Anthony F. |date=2015-11-22 |title=Consensual Nonmonogamy: Psychological Well-Being and Relationship Quality Correlates |journal=The Journal of Sex Research |language=en |volume=52 |issue=9 |pages=961–982 |doi=10.1080/00224499.2014.942722 |issn=0022-4499 |pmid=25189189}} In a swinging relationship a couple tend to engage in sexual activities with people other than their primary partner, typically at a party or in another social settings.{{Cite journal |last1=Matsick |first1=Jes L. |last2=Conley |first2=Terri D. |last3=Ziegler |first3=Ali |last4=Moors |first4=Amy C. |last5=Rubin |first5=Jennifer D. |date=2014-10-02 |title=Love and sex: polyamorous relationships are perceived more favourably than swinging and open relationships |journal=Psychology & Sexuality |language=en |volume=5 |issue=4 |pages=339–348 |doi=10.1080/19419899.2013.832934 |issn=1941-9899}} Polyamorous relationships are those in which people experience both sexual and emotional relationships with multiple partners concurrently, placing emphasis on a romantic and emotional aspects of the relationship, rather than on strictly sexual.{{Cite journal |last1=Grunt-Mejer |first1=Katarzyna |last2=Campbell |first2=Christine |date=2016-01-02 |title=Around Consensual Nonmonogamies: Assessing Attitudes Toward Nonexclusive Relationships |journal=The Journal of Sex Research |volume=53 |issue=1 |pages=45–53 |doi=10.1080/00224499.2015.1010193 |issn=0022-4499 |pmid=26241075 |url=https://research.stmarys.ac.uk/id/eprint/858/1/Grunt-Meyer%20%26%20Campbell%202015.pdf |language=en}} An open relationship is a relationship arrangement in which one or both partners seek sexual relationships independently of each other. Some authors suggest the concept of relationship anarchy, which describes intimate relationships characterised by principles aligned with anarchism, that include autonomy, the rejection of hierarchies, the absence of state intervention, rejection of societal norms, and a focus on community interdependence.{{Cite web |last=Nordgren |first=Andie |date=2006 |title=The short instructional manifesto for relationship anarchy |url=https://theanarchistlibrary.org/library/andie-nordgren-the-short-instructional-manifesto-for-relationship-anarchy |access-date=2024-04-04 |website=The Anarchist Library |language=en}} Unlike culturally institutionalised non-monogamy, CNM typically exists outside legal frameworks, as it does not involve formal marriage to multiple partners, but relies on mutual consent.
• Secretive non-monogamy (or non-consensual non-monogamy), commonly known as infidelity or cheating, refers to a situation in which one or both partners in a committed relationship engage in secret extra-dyadic sexual or romantic relationships with one or more additional partners, without the knowledge or consent of the other partner/s.{{Cite journal |last1=Kelberga (Kelberg) |first1=Anna |last2=Martinsone |first2=Baiba |date=2022-09-21 |title=Motivation of non-monogamous adults to engage in sex with their different partners |journal=Frontiers in Psychology |volume=13 |doi=10.3389/fpsyg.2022.961949 |doi-access=free |issn=1664-1078 |pmc=9533024 |pmid=36211920}}

It is important to note that the above-described categories are not mutually exclusive or collectively exhaustive as individual experiences often diverge from standard definitions due to the intricate nuances inherent in the complexity of human sexual relationships.{{Cite journal |last1=Scoats |first1=Ryan |last2=Campbell |first2=Christine |date=December 2022 |title=What do we know about consensual non-monogamy? |journal=Current Opinion in Psychology |language=en |volume=48 |pages=101468 |doi=10.1016/j.copsyc.2022.101468 |doi-access=free |pmid=36215906}} The fluid and complex nature of human sexual and romantic relationships allows for diverse expressions that may not fit neatly into a single category, with subtle nuances often blurring the boundaries between these forms.

Non-monogamy is practiced globally, but its prevalence varies significantly depending on cultural, legal, and societal factors.

• Culturally Institutionalised Non-Monogamy. Polygyny (a form of polygamy in which a man marries multiple women) is permitted in many Muslim-majority countries and is most often found in sub-Saharan Africa, where 11% of the population lives in arrangements that include more than one spouse.{{Cite web |last=Kramer |first=Stephanie |date=2020-12-07 |title=Polygamy is rare around the world and mostly confined to a few regions |url=https://www.pewresearch.org/short-reads/2020/12/07/polygamy-is-rare-around-the-world-and-mostly-confined-to-a-few-regions/?utm_source=chatgpt.com |access-date=2024-12-19 |website=Pew Research Center |language=en-US}} However, reliable statistics on the prevalence of polygamous marriages in Gulf countries and Sub-Saharan Africa are limited. Existing evidence suggests that while Islamic law permits polygamy in some regions, its actual practice is relatively uncommon and varies widely by country. For instance, the 2017–2018 Jordan Population and Family Health Survey found that approximately 4% of married women reported their husband had other wives, being most common among women with no education (13%).{{Cite web |date=2019 |title=Jordan Population and Family Health Survey 2017-18: Key Findings. |url=https://dhsprogram.com/pubs/pdf/SR256/SR256.pdf |place=Amman, Jordan, and Rockville, Maryland, USA |publisher=DOS and ICF}} In contrast, the 2017 Senegal DHS reported that 32% of married women were in polygynous unions, demonstrating that rates can differ significantly across regions.{{Cite web |publisher=Agence Nationale de la Statistique et de la Démographie (ANSD) [Sénégal], et ICF |date=2018 |title=Sénégal : Enquête Démographique et de Santé Continue (EDS-Continue) |url=https://dhsprogram.com/publications/publication-fr345-dhs-final-reports.cfm |access-date=}} Contemporary studies have identified 53 societies (out of over 1000) practicing polyandry (a form of polygamy in which a woman marries multiple men), though its prevalence within these societies is difficult to determine, with the highest recorded rate being approximately 12 percent.{{Cite book |last1=Blume |first1=Amelia |title=The Wiley Blackwell Encyclopedia of Family Studies |last2=Abrutyn |first2=Seth |date=2016 |publisher=The Wiley Blackwell Encyclopedia of Family Studies |publication-date=2016 |chapter=Polyandry. |pages=1–2 |doi=10.1002/9781119085621.wbefs119|isbn=978-1-119-08562-1 }} Polyandry is practiced in regions such as the Himalayan areas of India, Nepal, and Tibet, the Marquesas Islands in the South Pacific, and among indigenous groups like the Yanomamö in South America and the Inuit in the Arctic.
• Consensual non-monogamy. Studies suggest that CNM arrangements, such as open relationships and polyamory, are becoming increasingly visible in Western societies. It is estimated that 3%-7% of Americans,{{Cite journal |last1=Rubin |first1=Jennifer |last2=Moors |first2=Amy |last3=Matsick |first3=Jes |last4=Ziegler |first4=Ali |last5=Conley |first5=Terri |date=2014-01-01 |title=On the Margins: Considering Diversity Among Consensually Non-monogamous Relationships |journal=Psychology Faculty Articles and Research |url=https://digitalcommons.chapman.edu/psychology_articles/133}}{{Cite journal |last1=Haupert |first1=M. L. |last2=Moors |first2=Amy C. |last3=Gesselman |first3=Amanda N. |last4=Garcia |first4=Justin R. |date=2017 |title=Estimates and Correlates of Engagement in Consensually Non-Monogamous Relationships |url=http://link.springer.com/10.1007/s11930-017-0121-6 |journal=Current Sexual Health Reports |language=en |volume=9 |issue=3 |pages=155–165 |doi=10.1007/s11930-017-0121-6 |issn=1548-3584|url-access=subscription }} 2.5% of Canadians,{{Cite journal |last1=Fairbrother |first1=Nichole |last2=Hart |first2=Trevor A. |last3=Fairbrother |first3=Malcolm |date=2019-07-24 |title=Open Relationship Prevalence, Characteristics, and Correlates in a Nationally Representative Sample of Canadian Adults |journal=The Journal of Sex Research |volume=56 |issue=6 |pages=695–704 |doi=10.1080/00224499.2019.1580667 |issn=0022-4499 |pmid=30932711 |language=en}} around 3% of Norwegians,{{Cite journal |last1=Træen |first1=Bente |last2=Thuen |first2=Frode |date=2022-01-02 |title=Non-consensual and Consensual Non-monogamy in Norway |journal=International Journal of Sexual Health |language=en |volume=34 |issue=1 |pages=65–80 |doi=10.1080/19317611.2021.1947931 |issn=1931-7611 |pmc=10906970 |pmid=38595687 |hdl-access=free |hdl=11250/2822937}} and 3.3% of Dutch and Flemish{{Cite web |last1=Horsten |first1=Joost |last2=de Liefde |first2=Pluk |date=2017 |title=Hoeveel polyamoristen zijn er in Nederland en Vlaanderen? |url=https://www.plukdeliefde.nl/wp-content/uploads/2015/11/prevalentie-van-nonmonogamie-in-Nederland-en-Vlaanderen.pdf}} are engaged in consensual non-monogamy at an any given time and around a quarter of the Americans, Canadians, Norwegians, and Dutch and Flemish at least once have engaged in a consensually non-monogamous relationship in their lifetime.{{Cite journal |last1=Rubel |first1=Alicia N |last2=Burleigh |first2=Tyler J |date=February 2020 |title=Counting polyamorists who count: Prevalence and definitions of an under-researched form of consensual nonmonogamy |journal=Sexualities |language=en |volume=23 |issue=1–2 |pages=3–27 |doi=10.1177/1363460718779781 |issn=1363-4607|url=https://osf.io/st2k5 }} In two surveys in 2013 and 2014, one fifth of surveyed single United States adults had, at some point in their lives, engaged in consensual non-monogamy.{{Cite journal |last1=Haupert |first1=M. L. |last2=Gesselman |first2=Amanda N. |last3=Moors |first3=Amy C. |last4=Fisher |first4=Helen E. |last5=Garcia |first5=Justin R. |date=2017-07-04 |title=Prevalence of Experiences With Consensual Nonmonogamous Relationships: Findings From Two National Samples of Single Americans |journal=Journal of Sex & Marital Therapy |volume=43 |issue=5 |pages=424–440 |doi=10.1080/0092623X.2016.1178675 |issn=0092-623X |pmid=27096488 |s2cid=6855648}} YouGov poll reported that in 2020 about one-third of US adults believe that "their ideal relationship is non-monogamous to some degree" and in 2024 9% of Brits have been or would like to be in a polyamorous relationship.{{cite web |url=https://today.yougov.com/topics/relationships/articles-reports/2020/01/31/millennials-monogamy-poly-poll-survey-data |title=Millennials are less likely to want a monogamous relationship |last=Ballard |first=Jamie |date=January 31, 2020 |website=YouGov |access-date=December 24, 2020 |archive-url=https://web.archive.org/web/20201103194338/https://today.yougov.com/topics/relationships/articles-reports/2020/01/31/millennials-monogamy-poly-poll-survey-data |archive-date=November 3, 2020 |url-status=live}}{{Cite web |title=How Brits feel about polyamory |url=https://yougov.co.uk/topics/society/trackers/how-brits-feel-about-polyamory |access-date=2024-12-23 |website=yougov.co.uk |language=en-gb}}
• Secretive non-monogamy. Measuring the prevalence of infidelity presents significant methodological challenges, as estimates vary depending on the research design, sample population, and the definition of adultery used by the researchers. Studies differ in whether they categorize infidelity as sexual, emotional, or both, and they rely on respondents’ subjective interpretations of what behaviors qualify as unfaithful – ranging from sexual intercourse to kissing, or even online interactions like cybersex. Additionally, infidelity is often underreported due to associated guilt and shame, leading to potential biases in self-reported data.{{Cite journal |last1=Blow |first1=Adrian J. |last2=Hartnett |first2=Kelley |date=April 2005 |title=Infidelity in Committed Relationships I: A Methodological Review |journal=Journal of Marital and Family Therapy |language=en |volume=31 |issue=2 |pages=183–216 |doi=10.1111/j.1752-0606.2005.tb01555.x |pmid=15974058 |issn=0194-472X}}{{Cite journal |last1=Fincham |first1=Frank D |last2=May |first2=Ross W |date=2017 |title=Infidelity in romantic relationships |journal=Current Opinion in Psychology |language=en |volume=13 |pages=70–74 |doi=10.1016/j.copsyc.2016.03.008|pmid=28813298 }} Typically, studies report infidelity rates in the range from 25% to 75%.{{Cite journal |last1=Eaves |first1=Susan H. |last2=Robertson-Smith |first2=Misty |date=2007 |title=The Relationship Between Self-Worth and Marital Infidelity: A Pilot Study |journal=The Family Journal |volume=15 |issue=4 |pages=382–386 |doi=10.1177/1066480707305468 |issn=1066-4807}}{{Cite journal |last1=Allen |first1=Elizabeth S. |last2=Atkins |first2=David C. |last3=Baucom |first3=Donald H. |last4=Snyder |first4=Douglas K. |last5=Gordon |first5=Kristina Coop |last6=Glass |first6=Shirley P. |date=2005 |title=Intrapersonal, Interpersonal, and Contextual Factors in Engaging in and Responding to Extramarital Involvement. |journal=Clinical Psychology: Science and Practice |language=en |volume=12 |issue=2 |pages=101–130 |doi=10.1093/clipsy.bpi014 |issn=1468-2850}}{{Cite journal |last1=Wiederman |first1=Michael W. |last2=Hurd |first2=Catherine |date=1999-04-01 |title=Extradyadic Involvement during Dating |journal=Journal of Social and Personal Relationships |language=en |volume=16 |issue=2 |pages=265–274 |doi=10.1177/0265407599162008 |issn=0265-4075}}{{Cite book |title=The state of affairs: explorations in infidelity and commitment |date=2004 |publisher=Lawrence Erlbaum Associates |isbn=978-1-4106-1065-2 |editor-last=Duncombe |editor-first=Jean |series=LEA's series on personal relationships |location=Mahwah, N.J |chapter=Communication and Marital Infidelity by Anita L. Vangelisti, Mandi Gerstenberger}} Infidelity is generally more common among cohabiting and dating couples than married couples and has been found to show seasonal variation, peaking during summer months due to travel and reduced chances of detection.{{Cite journal |last=Adamopoulou |first=Effrosyni |date=2013 |title=New facts on infidelity |url=https://linkinghub.elsevier.com/retrieve/pii/S0165176513004321 |journal=Economics Letters |language=en |volume=121 |issue=3 |pages=458–462 |doi=10.1016/j.econlet.2013.09.025|url-access=subscription }}{{Cite journal |last1=Treas |first1=Judith |last2=Giesen |first2=Deirdre |date=2000 |title=Sexual Infidelity Among Married and Cohabiting Americans |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1741-3737.2000.00048.x |journal=Journal of Marriage and Family |language=en |volume=62 |issue=1 |pages=48–60 |doi=10.1111/j.1741-3737.2000.00048.x |issn=1741-3737|url-access=subscription }} While older studies report men engaging in infidelity more often than women, more recent studies report that men and women engage in infidelity at similar rates. However, men tend to report their extra-dyadic relationships as more sexual, while women report theirs as more emotional.

Polygyny is legally recognised and regulated in many Muslim-majority countries, where Islamic law permits a man to marry up to four wives under specific conditions. In some countries like Saudi Arabia, Iran, Qatar, Jordan, Yemen, Algeria, and Mauritania polygyny is legal and regulated by a Family Law.{{Cite book |last=Welchman |first=Lynn |doi=10.5117/9789053569740 |title=Women and Muslim Family Laws in Arab States : A Comparative Overview of Textual Development and Advocacy |date=2007 |publisher=Amsterdam University Press |isbn=978-90-5356-974-0 |location=Amsterdam|doi-broken-date=23 December 2024 }} In other countries like Pakistan, Egypt, Iraq, Syria, Morocco, Indonesia and Malaysia polygyny is allowed only under conditions like first wife’s disability or infertility, requires the written consent of the first wife and sometimes of a judge. However, over the past several decades, some of the Muslim-majority countries have experienced significant reforms in Muslim Family Law and several countries have taken steps to ban polygyny, reflecting changing societal attitudes and efforts to promote gender equality. For example, Tunisia banned polygyny as part of its family law reform under president Habib Bourguiba in 1956.{{Cite book |last=Charrad |first=Mounira |editor-first1=Mounira |editor-last1=Charrad |doi=10.1525/9780520935471 |title=States and Women's Rights |date=2002-12-31 |publisher=University of California Press |isbn=978-0-520-93547-1}} As part of Mustafa Kemal Atatürk's secular reforms, Turkey banned polygyny in 1926, replacing Islamic family law with a Swiss-inspired civil code.{{Cite SSRN |last=Yilmaz |first=Ihsan |date=2018 |title=Semi-Official Turkish Muslim Legal Pluralism: Encounters between Secular Official Law and Unofficial Shariia |ssrn=3173990}} In Kazakhstan, Uzbekistan, Kyrgyzstan, and Tajikistan polygyny was prohibited under Soviet law and these bans were reaffirmed or codified into new national family laws in 1998 after these countries regained independence.{{Cite book |last=Thibault |first=Hélène |title=The Many Faces of Polygyny in Kazakhstan. |date=2021 |publisher=Central Asia Program Papers.}}{{Cite web |last=Shields |first=Acacia |date=2006 |title=Reconciled to Violence State Failure to Stop Domestic Abuse and Abduction of Women in Kyrgyzstan |url=https://www.hrw.org/report/2006/09/27/reconciled-violence/state-failure-stop-domestic-abuse-and-abduction-women |publisher=Human Rights Watch}}

Polyandry is considered incompatible with Sharia law and is therefore not recognised in Muslim-majority countries.{{Cite journal |last=Moosa |first=N |date=2009-09-24 |title=Polygynous Muslim Marriages in South Africa: Their Potential Impact on the Incidence of HIV/AIDS |journal=Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad |volume=12 |issue=3 |doi=10.4314/pelj.v12i3.46271 |doi-access=free |issn=1727-3781}} Polyandry persists informally in certain traditional societies, such as in the Himalayan regions of Tibet and Nepal, where fraternal polyandry helps preserve family property and manage limited agricultural land, and among communities like the Toda tribe in South India and parts of Himachal Pradesh, though it is not legally recognised.{{Cite journal |last=Childs |first=Geoff |date=January 2003 |title=Polyandry and population growth in a historical Tibetan society |journal=The History of the Family |language=en |volume=8 |issue=3 |pages=423–444 |doi=10.1016/S1081-602X(03)00045-9 |issn=1081-602X}}{{Cite web |last=Hays |first=Jeffrey |title=POLYANDRY (MARRIAGE TO MULTIPLE HUSBANDS) IN TIBET |website=Facts and Details |url=https://factsanddetails.com/china/cat6/sub35/entry-4434.html?utm_source=chatgpt.com |access-date=2024-12-22 |language=en}}

In the United States, Canada, all European countries, and Russia, marriage is legally defined as a union between two individuals, and no form of polygamy is legally recognised.{{Cite book |last1=Bailey |first1=Martha |title=Polygamy in the monogamous world: multicultural challenges for Western law and policy |last2=Kaufman |first2=Amy J. |date=2010 |publisher=Praeger |isbn=978-0-313-37952-9 |location=Santa Barbara, Calif |oclc=502674978}} In the United States and Canada, polygamy is strictly prohibited, with violations resulting in criminal penalties such as fines or imprisonment.{{Cite journal |last=McIssac |first=Ian A |date=2017-03-03 |title=Reference Re Supreme Court Act: Atlantic Canada and Regional Considerations in Supreme Court of Canada Appointments |journal=Constitutional Forum / Forum Constitutionnel |volume=26 |issue=1 |pages=9 |doi=10.21991/c90t1m |issn=1927-4165|doi-access=free }} Across Europe, polygamous marriages are not recognised due to public policy conflicts, gender equality principles, and fundamental legal values. For example, in France and Germany, polygamy is not recognised under civil law, and attempts to enter into such unions can result in criminal charges, denial of marital benefits, or annulment of subsequent marriages. Polygamy is broadly unrecognised in European countries, posing challenges for asylum seekers with multiple spouses, as typically only one spouse is granted a residence permit and international protection.{{Cite web |date=2016 |title=European Migration Network Ad-Hoc Query on Polygamous marriage |url=https://home-affairs.ec.europa.eu/system/files/2020-09/ad-hoc-queries-1032_es_polygamous_marriage_wider_diss_protection.pdf |website=European Commission}} However, some countries may evaluate such cases individually, considering specific circumstances.{{Cite web |last=Iversen |first=Michelle Rinaldo |date=2017 |title=The legal status of polygamy in England and Germany - a comparison Domicile vs. Nationality |url=http://lup.lub.lu.se/student-papers/record/8908030 |access-date=}}{{Citation |last1=Strik |first1=Tineke |title=Family Reunification: A Barrier or Facilitator of Integration? A Comparative Study |date=2014 |work=Freiheit |pages=92–108 |url=https://doi.org/10.5771/9783845252759-92 |access-date=2024-12-23 |publisher=Nomos Verlagsgesellschaft mbH & Co. KG |last2=Nissen |first2=Ellen|doi=10.5771/9783845252759-92 |isbn=978-3-8452-5275-9 |url-access=subscription }}{{Citation |last=Zaccaroni |first=Giovanni |title=Polygamous Marriages and Reunification of Families on the Move Under EU Law: An Overview |date=2024 |work=Children in Migration and International Family Law |pages=313–323 |editor-last=Arnold |editor-first=Stefan |url=https://link.springer.com/10.1007/978-3-031-71598-3_20 |access-date=2024-12-23 |place=Cham |publisher=Springer Nature Switzerland |language=en |doi=10.1007/978-3-031-71598-3_20 |isbn=978-3-031-71597-6 |editor2-last=Heiderhoff |editor2-first=Bettina|url-access=subscription }}

Unlike polygamy, CNM does not involve multiple legally recognised marriages but instead consists of consensual agreements between adults to engage in multiple romantic or sexual relationships. This distinction allows CNM to operate within the bounds of the law in jurisdictions where monogamy is the legal marital standard. At the same time, the lack of legal recognition for CNM relationships means they are excluded from many legal protections, such as inheritance rights, hospital visitation, spousal visas, and parental responsibilities, as existing legal frameworks typically do not accommodate multiple concurrent partnerships.{{Cite journal |last1=Füllgrabe |first1=Doris |last2=Smith |first2=David S. |date=2023-10-01 |title="Monogamy? In this Economy?": Stigma and Resilience in Consensual Non-Monogamous Relationships |journal=Sexuality & Culture |language=en |volume=27 |issue=5 |pages=1955–1976 |doi=10.1007/s12119-023-10099-7 |issn=1936-4822|doi-access=free }}{{Cite SSRN |last=Emens |first=Elizabeth F. |date=2004 |title=Monogamy's Law: Compulsory Monogamy and Polyamorous Existence |ssrn=506242}} However, in recent years Canada and some of the U.S. states have taken steps toward recognising CNM relationships. In April 2018, the Newfoundland and Labrador Supreme Court in Canada recognized three adults in a polyamorous relationship as the legal parents of a child, marking a significant precedent in family law.{{Cite journal |last=Challborn |first=Margot R. |date=2024 |title=Polyamory and Legal Parentage: The Possibilities of C.C. (Re) and BCSC 767 for Expanding Conceptions of Kinship in Canada |url=https://link.springer.com/10.1007/s10691-023-09539-4 |journal=Feminist Legal Studies |language=en |volume=32 |issue=3 |pages=331–351 |doi=10.1007/s10691-023-09539-4 |issn=0966-3622|url-access=subscription }} Similarly, in June 2020, Somerville, Massachusetts, became the first U.S. city to adopt an ordinance permitting domestic partnerships involving more than two adults, thereby legally recognising CNM relationships.{{Cite web |last=hlr |date=2022-03-10 |title=Three's Company, Too: The Emergence of Polyamorous Partnership |url=https://harvardlawreview.org/print/vol-135/threes-company-too-the-emergence-of-polyamorous-partnership-ordinances/#:~:text=In%20the%20summer%20of%202020,legal%20recognition%20of%20their%20relationships. |access-date=2024-12-23 |website=Harvard Law Review |language=en-US}}

Consensually non-monogamous relationships have no legal recognition in Muslim-majority countries, and extramarital relationships, even consensual, are typically criminalised.{{Cite web |last=Hosseini |first=Ziba Mir |date=2010 |title=Criminalizing Sexuality: Zina Laws as Violence Against Women in Muslim Contexts |url=https://documentation.lastradainternational.org/lsidocs/islamic.pdf}}

Secretive non-monogamy (non-consensual non-monogamy), commonly referred to as infidelity or adultery, is addressed differently across global legal frameworks, with variations based on cultural, religious, and societal norms. In most Western nations like the United States, Canada, and much of Europe, while viewed as a moral transgression, infidelity is not punishable under criminal law.{{Citation |last=Kršljanin |first=Nina |title=Adultery as a Crime in the Western World and Beyond: From a Man's Property to (In)Fidelity, from Discrimination to Decriminalization |date=2023 |work=Feminist Approaches to Law |series=Gender Perspectives in Law |volume=1 |pages=129–150 |editor-last=Vujadinović |editor-first=Dragica |url=https://link.springer.com/10.1007/978-3-031-14781-4_6 |access-date=2024-12-24 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-14781-4_6 |isbn=978-3-031-14780-7 |editor2-last=Álvarez del Cuvillo |editor2-first=Antonio |editor3-last=Strand |editor3-first=Susanne|url-access=subscription }} Conversely, in several Muslim-majority countries and others with laws influenced by religious doctrine, infidelity is criminalised under adultery laws. Countries such as Saudi Arabia, Iran, and Pakistan classify extramarital relationships as criminal acts, with punishments ranging from fines and imprisonment to flogging or, in extreme cases, capital punishment. Marital infidelity is explicitly recognised as grounds for divorce under the laws of Iraq, Algeria and the United Arab Emirates. In some jurisdictions, infidelity laws apply differently based on gender, with women often facing harsher consequences than men.{{Cite web |last=katharina.kiener-manu |title=Crime Prevention & Criminal Justice Module 9 Key Issues: Topic 1 - Gender-based discrimination and women in conflict with the law |url=https://www.unodc.org/e4j/en/crime-prevention-criminal-justice/module-9/key-issues/1--gender-based-discrimination-and-women-in-conflict-with-the-law.html |access-date=2024-12-24 |website=www.unodc.org |language=en}}

In Western cultures, monogamy is widely regarded as superior to relationships involving multiple partners. This preference for monogamous relationships is often referred to as mononormativity or monocentrism.

Consensually non-monogamous individuals face widespread stigma and are often misunderstood due to various stereotypes and myths. One of them is that those in CNM relationships are primarily motivated by a desire for more sex, leading to an increased risk of sexually transmitted infections. Studies have found that individuals practicing consensual non-monogamy are more likely to engage in safer sex practices and less likely to use condoms incorrectly compared to individuals who engage in extra-dyadic sex within ostensibly monogamous relationships{{Cite journal |last1=Conley |first1=Terri D. |last2=Ziegler |first2=Ali |last3=Moors |first3=Amy C. |last4=Matsick |first4=Jes L. |last5=Valentine |first5=Brandon |date=2013 |title=A Critical Examination of Popular Assumptions About the Benefits and Outcomes of Monogamous Relationships |url=https://journals.sagepub.com/doi/10.1177/1088868312467087 |journal=Personality and Social Psychology Review |language=en |volume=17 |issue=2 |pages=124–141 |doi=10.1177/1088868312467087 |pmid=23175520 |issn=1088-8683|url-access=subscription }}{{Cite journal |last1=Conley |first1=Terri D. |last2=Moors |first2=Amy C. |last3=Matsick |first3=Jes L. |last4=Ziegler |first4=Ali |date=2012-06-04 |title=The Fewer the Merrier?: Assessing Stigma Surrounding Consensually Non-monogamous Romantic Relationships |url=https://doi.org/10.1111/j.1530-2415.2012.01286.x |journal=Analyses of Social Issues and Public Policy |volume=13 |issue=1 |pages=1–30 |doi=10.1111/j.1530-2415.2012.01286.x |issn=1529-7489|hdl=2027.42/102091 |hdl-access=free }} or compared to monogamous population.{{Cite journal |last=Jj |first=Lehmiller |date=October 2015 |title=A Comparison of Sexual Health History and Practices Among Monogamous and Consensually Nonmonogamous Sexual Partners |journal=The Journal of Sexual Medicine |language=en |volume=12 |issue=10 |pages=2022–2028 |doi=10.1111/jsm.12987 |pmid=26395880}} This can be explained by the fact tha CNM individuals tend to prioritize open communication and explicit agreements about sexual boundaries, which often include discussions about safer sex practices. Several studies have explored societal attitudes toward different forms of CNM relationships, but the findings are often conflicting and inconclusive. While some research indicates more positive attitudes toward polyamorous relationships,{{Cite journal |last1=Matsick |first1=Jes L. |last2=Conley |first2=Terri D. |last3=Ziegler |first3=Ali |last4=Moors |first4=Amy C. |last5=Rubin |first5=Jennifer D. |date=2014-10-02 |title=Love and sex: polyamorous relationships are perceived more favourably than swinging and open relationships |url=http://www.tandfonline.com/doi/abs/10.1080/19419899.2013.832934 |journal=Psychology & Sexuality |language=en |volume=5 |issue=4 |pages=339–348 |doi=10.1080/19419899.2013.832934 |issn=1941-9899|url-access=subscription }}{{Cite journal |last1=Grunt-Mejer |first1=Katarzyna |last2=Campbell |first2=Christine |date=2016-01-02 |title=Around Consensual Nonmonogamies: Assessing Attitudes Toward Nonexclusive Relationships |url=https://www.tandfonline.com/doi/full/10.1080/00224499.2015.1010193 |journal=The Journal of Sex Research |language=en |volume=53 |issue=1 |pages=45–53 |doi=10.1080/00224499.2015.1010193 |pmid=26241075 |issn=0022-4499}} emphasising emotional and romantic connections, other studies suggest that swinging or group sex, which focus primarily on sexual activity,{{Cite journal |last1=Thompson |first1=Ashley E. |last2=Hart |first2=Jocelyn |last3=Stefaniak |first3=Sarah |last4=Harvey |first4=Carissa |date=2018 |title=Exploring Heterosexual Adults' Endorsement of the Sexual Double Standard among Initiators of Consensually Nonmonogamous Relationship Behaviors |url=http://link.springer.com/10.1007/s11199-017-0866-4 |journal=Sex Roles |language=en |volume=79 |issue=3–4 |pages=228–238 |doi=10.1007/s11199-017-0866-4 |issn=0360-0025|url-access=subscription }} are viewed more favourably.

Social attitudes toward secretive non-monogamy are overwhelmingly negative across most cultures. While being the most prevalent form of non-monogamy and as common as monogamy, secretive non-monogamy is widely condemned due to its association with betrayal, dishonesty, and the violation of trust within relationships. Factors such as societal gender norms, power dynamics, and the perceived acceptability of infidelity within certain contexts (e.g., among men versus women) influence attitudes toward non-consensual non-monogamy.

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Non-monogamy introduces unique challenges to involved partners, such as managing emotions like jealousy, maintaining trust and boundaries, and navigating social stigmas. Couples are more likely to adapt positively to non-monogamy if specific foundational conditions are met. This includes both partners wanting their relationship to remain primary, the couple having an established reservoir of good will, and a minimum of lingering resentments from past hurts and betrayals.{{cite journal |last=Shernoff |first=M |year=2006 |title=Negotiated nonmonogamy and male couples. |url=http://www.familyprocess.org/Data/featured_articles/65_shernoff.pdf |journal=Family Process |volume=45 |issue=4 |pages=407–18 |doi=10.1111/j.1545-5300.2006.00179.x |issn=0014-7370 |pmid=17220111 |archive-url=https://web.archive.org/web/20130429022859/http://www.familyprocess.org/Data/featured_articles/65_shernoff.pdf |archive-date=2013-04-29}} A shared agreement on the decision to pursue non-monogamy, along with a sense of equality and autonomy between partners, is also crucial in building trust and navigating the complexities of a non-exclusive arrangement. Studies emphasise the importance of direct communication between partners. Key topics for discussion include the degree of openness versus secrecy in their arrangement, ensuring voluntary participation and avoiding coercion and inequality, and clarity versus vagueness.

While it is tempting to categorise non-monogamy in broad categories, human relationships are complex and multifaceted with many terms emerging to reflect the nuanced nature of non-monogamous arrangements. Some people use the term "monogamish" to describe relationships that are primarily monogamous but allow for some degree of flexibility in terms of sexual or romantic experiences outside the primary partnership.{{Cite journal |last1=Mogilski |first1=Justin |last2=Rodrigues |first2=David L. |last3=Lehmiller |first3=Justin J |last4=Balzarini |first4=Rhonda Nicole |date=2021-06-08 |title=Maintaining multi-partner relationships: Evolution, sexual ethics, and consensual non-monogamy |doi=10.31234/osf.io/k4r9e |url=https://doi.org/10.31234/osf.io/k4r9e |journal=PsyArXiv |access-date=2024-12-26|hdl=10071/31924 |hdl-access=free }} Partners in such relationships may, for example, agree to occasional flings, participation in group activities, or other consensual experiences that do not threaten the emotional core of their partnership. Similarly, the term "don't ask, don't tell" is used to describe a relationship arrangement where partners tacitly agree to allow sexual or romantic activities outside the primary relationship, but without explicitly discussing or disclosing the details of those activities.{{Cite book |doi=10.1002/9781394259298.ch19 |chapter=Gender in Counselling Psychology |title=Counselling Psychology - A textbook for study and practice |date=2015 |last1=Barker |first1=MEG-John |last2=Richards |first2=Christina |pages=281–296 |isbn=978-1-119-10685-2 |url=https://oro.open.ac.uk/50710/1/BarkerRichardsCounsellingPsychology2017.docx }}

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• Adultery
• Extramarital sex
• Group sex
• List of polyamorous characters in fiction
• Plaçage
• Polyday
• Romantic orientation
• Sexual revolution
• The Four Loves (Book)

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{{Reflist}}

Category:Sexual fidelity

Category:Intimate relationships