Ethical non-monogamy is a relationship structure where all involved parties consent to have multiple romantic or sexual relationships, with honesty and open communication. Unlike cheating, all actions are aboveboard and ethically conducted, with respect for everyone’s boundaries and feelings.
Key Points
- Umbrella Term: Ethical non-monogamy (ENM) covers relationships that are not exclusive between two people, as long as everyone involved consents.
- Vs. Monogamy: In monogamy, two partners are exclusive with one another and do not pursue romantic or intimate relationships with anyone else.
- Consent and Honesty: People who practice ENM are expected to be considerate and honest with every partner involved.
- Who’s Involved: One or both partners can pursue outside connections, and a person may also be involved with someone who has multiple partners of their own.
- Not Cheating: ENM differs from cheating because everyone consents to, and is happy with, the arrangement.
- Outcomes: Reviews of the research find that consensually non-monogamous people report relationship satisfaction comparable to monogamous people, though most studies use self-selected samples.
Ethical Non-Monogamy Definition and Key Differences
ENM differs from non-monogamy in general in one key way: agreed consent between everyone involved in the relationship.
In contrast, without the word ethical, people can engage in outside relations without the knowledge or consent of everyone involved.
ENM is also not the same as infidelity or cheating.
Infidelity means that a partner in an exclusive relationship has a romantic or intimate relationship with someone outside their relationship without the knowledge or consent of their partner.
When someone is cheating, they are not communicating ethically. They are lying, deceiving, and disrespecting their partner.
What defines ENM is consent and honesty, not how many partners are involved. Researchers more often call the same territory consensual non-monogamy (CNM). The two terms are used largely interchangeably, with “ethical” stressing honesty rather than deception.
Is Ethical Non-Monogamy Accepted?
Society often teaches us that relationships should follow a set structure, and it defines what counts as acceptable.
Society and the media will usually display monogamous relationships as the norm and something everyone should strive for, and many people may not realize that there are other options.
Since the concept is thought to be relatively new, it can be difficult to broach the topic of ENM with friends and family.
Many people who engage in ENM may do so discreetly because they fear the judgment that may follow if they share that their relationships are ENM.
There is a harmful stereotype that those who engage in ENM are cheating or do not truly care for their partners. That fear is real. That stereotype can make it difficult for people to share details about their relationships.
Researchers call the underlying assumption mono-normativity: the unstated belief that lifelong exclusivity is the natural, correct, and healthiest way to have a relationship.
The stigma is measurable. Conley and colleagues found that people rated monogamous relationships more positively than consensually non-monogamous ones on every dimension examined, even arbitrary traits unrelated to relationships. That held across diverse social groups, including non-monogamous people themselves (Conley et al., 2013).
Yet ENM is not a fringe practice. Surveys of single American adults find that a meaningful minority report having practiced some form of consensual non-monogamy (Haupert et al., 2017).
Types of Ethical Non-Monogamy
ENM is an umbrella term for many types of relationships. ENM can be practiced without following a specific relationship model and can comprise whatever rules that all parties agree on.
Nonetheless, there are several types of ENM relationship. Here they are in brief, with detail on each below:
- Polyamory: more than one romantic or intimate relationship at once, sometimes with primary and secondary partners.
- Open relationships: one or both partners pursue sex, and sometimes emotional attachment, outside the couple, usually casually.
- Monogamish: a mostly monogamous couple who occasionally take part in outside relations.
- Relationship anarchy: every relationship, romantic or platonic, treated as equally important, with no ranking.
- Polygamy: marriage to more than one spouse, ethical only when every party genuinely consents.
- Polyfidelity: several partners who keep romantic and sexual activity within a defined group.
- ENM marriage: spouses agree, with transparency and consent, to outside romantic or sexual relationships.
Polyamory
Polyamory means having more than one relationship. These can be romantic or intimate in nature.
Polyamory takes several forms:
- Triad: a relationship of three partners.
- Quad: a relationship of four partners.
- Hierarchical: one person has a prioritized primary partner and one or more secondary partners, any of whom may have additional partners.
- Nonhierarchical: relationships are not ranked, and each develops on its own terms.
Open relationships
Opening the relationship means that one or both partners can pursue sex and sometimes emotional attachments to other people outside the relationship.
The difference to polyamory is that relations outside of the primary relationship are typically casual and non-committal. The primary partner remains the most prioritized.
Partners in an open relationship more often pursue outside connections independently, rather than together as a couple.
Monogamish
This means a couple is monogamous most of the time but will occasionally take part in outside relations.
This is usually not often, for example, a couple may engage in sexual or other romantic relations with outsiders once and then not again for 5 years or more.
Relationship anarchy
Most people place their romantic relationship above all other relationships, including friendships and family. Relationship anarchists reject that ranking. They treat all types of relationships as equally important.
They do not automatically prioritize their spouse over their platonic friendships for example. This means they would not use the terms ‘primary/secondary partner/s.’
They may only choose to have one romantic partner but they are considered ENM as they value outside relationships as equally important as their romantic ones.
Polygamy
Polygamy is marriage to more than one spouse at a time. Polygyny is one husband with multiple wives; polyandry is one wife with multiple husbands.
Polygamy appears in a number of religious texts, and some sects still practice it today.
It can be practiced ethically. Some documented cases, though, have involved coercion and exploitation (Heath et al., 2016).
It is only ethical when every party genuinely consents to the arrangement.
Polyfidelity
This type of ENM is where there can be multiple romantic or sexual partners who are restricted to romantic or sexual activity only to members within the group.
The group may be open to allow other members to join, but there are often no romantic or sexual encounters with the new addition until they are added.
ENM Marriage
ENM marriage refers to a marital arrangement where both spouses agree, with transparency and consent, to engage in multiple romantic or sexual relationships outside of their union.
This approach emphasizes open communication, honesty, and respect for all involved parties, distinguishing it from infidelity.
Each version looks different. Examples include polyamory, open marriages, and swinging. Swinging is couples having sex with other people, often as a shared activity, without polyamory’s deeper emotional attachment.
How the Types Differ
The forms differ mainly in how outside connections work and how emotionally involved they are.
| Form | Outside connections | Emotional involvement |
|---|---|---|
| Open relationship | Partners more often pursue them independently, with the primary couple at the centre. | Mostly sexual and casual. |
| Swinging | The couple attends events together to have sex as a shared activity. | Sexual rather than emotionally committed. |
| Hierarchical polyamory | Ongoing relationships, with a primary couple kept at the top. | Emotional attachment extends to outside partners. |
| Nonhierarchical polyamory (including relationship anarchy) | Ongoing relationships, with no ranking of one over another. | Emotional attachment extends to outside partners. |
Why choose ethical non-monogamy?
People give many reasons for choosing ENM. Research on stated motivations finds a recurring cluster, including the following (Wood et al., 2021):
- Other needs: meeting needs a single partner cannot.
- Stronger relationship: outside relationships can strengthen the primary one.
- Sexual exploration: exploring sexuality without giving up a strong relationship.
- Sharing love: treating romantic love as something that is not used up by being shared.
- Avoiding a breakup: not ending a strong relationship over attraction to someone else.
To fulfill other needs
People who engage in ENM may do so to meet other needs they may have that their present relationship cannot provide.
Often, in monogamous relationships, there is the expectation that your one partner must fulfill every need that you have for the relationship to work.
Not every need fits one person.
Many who are ENM believe that putting these expectations on a partner is unreasonable. You cannot expect one person to meet every need you have, just as they cannot expect everything from you.
It can be a burden on others and can lead to disappointment or relationship breakdowns. That is a lot to ask of one person.
ENM allows people to look for others with similar romantic or sexual interests that their partner does not have or is not comfortable exploring.
This also allows your partner the chance to explore things that you may not be interested in. This is not to say that their relationship lacks something, but that there is more to gain from others to strengthen it.
“I am so happy this person makes them happy too, because it doesn’t take away from what I give them – that is something we had – which is sometimes hard to remember”
To strengthen their relationship
While it might sound unusual, engaging in relationships outside of the primary partner might strengthen the relationship they have together.
Many people who practice ENM credit it with pushing them toward stronger communication and a higher baseline of honesty. There is less need to hide anything from a partner.
“I love the growth part of it. I don’t think there’s anything where you grow as much, where you have to reflect as much, be aware of yourself as much and be forced to communicate as much”.
To explore their sexuality
Some people may not have had the chance to explore their sexuality before settling down with one person.
They may be extremely happy with their current partner. Even so, they may feel they missed out on experimenting with people of different genders if they never had the chance.
ENM may then make sense for someone to explore their sexuality without having to give up the relationship they have.
To share the love they can offer
Some people who engage in ENM point to human nature. They argue it is normal to want more than one romantic connection.
It is already normal to love more than one friend, family member, or child at once. Why, they ask, should romantic relationships be so restricted?
They may feel that having one romantic relationship limits the amount of love they have to share with others. Some people feel most like themselves when they can love two or more people.
To not have to end a relationship
Some people have a very strong relationship with their partner but find they are attracted to someone else too.
They do not want to end it, or to cheat. But monogamous norms pressure them to pick one person.
Many people end strong relationships for exactly this reason, believing they must choose one partner or the other.
ENM offers another option: pursuing both, as long as everyone involved discusses and consents to the arrangement.
Challenges of Ethical Non-Monogamy
Below are some considerations and potential limitations of engaging in ENM:
Social stigma and judgment
People who engage in ENM may face judgment from those outside of the community, including family members, friends, and therapists.
The stigma associated with ENM can make it difficult to be open about relationship choices and could lead to feelings of shame and isolation.
For example, one participant in a study shared that a negative experience involved “dealing with family members when they found out about our lifestyle and we were judged by them. It was none of their business.” (Scipione, 2021).
Jealousy and insecurity
Even in consensual ENM, jealousy and insecurity can arise, even when individuals consciously choose to live this way.
One or more partner may have been enthusiastic about the idea of ENM, but then later discovered that they do not like ‘sharing’ their partner with others.
Some people feel the flip side, called compersion. Compersion is a feeling of genuine pleasure in a partner’s happiness with someone else, rather than threat or loss.
It is not automatic, and where it develops, it usually comes gradually, through repeated experience and reflection on what a person actually wants for a partner.
“Instead of saying what they really felt, they said what they wanted to feel, what they thought they should feel. And both were somewhat in denial about their jealousy and wanted to deny it in order to preserve the freedom of sleeping around.”
Communication challenges
ENM relationships require open, honest communication and ongoing negotiation to thrive.
People who engage in this need to make sure their partner/s are trustworthy.
Navigating multiple relationships can be complex, and without clear communication and agreed-upon boundaries, misunderstandings and hurt feelings are more likely.
“I think people have to be honest, and not all people are honest. So that can ruin it.”
Potential for exploitation and abuse
As with any relationship style, there is a potential for toxic or abusive relationships in ENM.
A relationship with one partner can start off looking healthy. Later on, that person may show their true colors, become controlling, or try to isolate someone from their other partner or partners.
It’s essential for individuals to be aware of power dynamics, consent, and their own boundaries within these relationships, and to keep reflecting on whether this lifestyle is suited to them.
Legal and Institutional Barriers
Many legal and administrative systems assume a single romantic partner. Marriage law in most jurisdictions recognizes only two-party unions. Health insurance, next-of-kin, and inheritance rules are typically built around one named partner.
People who want legal or institutional recognition for more than one relationship must therefore work within frameworks that were not designed for them. That gap is separate from how well any individual relationship is working.
Children add another layer.
Polyamorous family and parenting is one of seven active domains of research on consensual non-monogamy (Gupta et al., 2023). Legal and social uncertainty remains over how existing custody and family frameworks apply to households with more than two parenting adults.
Practicing Ethical Non-Monogamy
If you are already in an exclusive relationship but want to try ENM, there are some steps you can take. Here is how to raise it with your partner:
Ensure the relationship you have is strong
ENM is not for everyone, and it may not be suitable for some couples, especially if they are experiencing relationship difficulties.
Remember that ENM will not fix a relationship that is already breaking down. Make sure your relationship is strong, and resolve any existing issues, before introducing ENM.
Timing matters too. Starting from a stable base is very different from proposing ENM after one partner discovers the other’s undisclosed outside involvement. In that crisis, opening the relationship cannot replace repairing the broken trust.
Consider your capacity
It’s essential to consider whether you have the capacity in your life for additional connections or relationships.
While love is not a limited resource, you may have limited time or emotional bandwidth. That means the amount of room you feel you have in your life for emotional attachments.
“Be very careful to not overwhelm and overbook yourself to the point you’re neglecting others and your own well-being. While love may be a limitless resource, time and attention are not.”
Discuss what you would both like to gain
Communicate openly and honestly with your partner about what you would like and offer them the opportunity to also express what they want.
Discuss what kind of relationship you would like to get into and the aspects of it that would suit both of you. You can discuss timeframes and long-term relationship goals to aim for.
Reassure your partner
Your partner may feel taken aback by your proposal. Reassure them that you are not seeking other relationships because they lack something.
Reassure them that with ENM, you can both add more to an already strong and healthy relationship.
Set clear boundaries
Ensure that you and your partner set clear boundaries and expectations for what is allowed in the relationship.
The boundaries can help protect you from the fears you may have. You and your partner can make a list of what you are fearful of and make it a rule that those boundaries are not crossed into outside relationships.
“A boundary is simply this: it is one thing, it is something that you put on yourself. […] Your boundary cannot be ‘my boundary is for my partner to do this’ or ‘my partner not to do that.'”
Negotiate
You cannot always meet everyone’s needs perfectly. It helps to negotiate a place in the middle: one partner may be ‘all in’ while the other stays more cautious.
Communication works best when everyone feels heard, with as little judgment as possible.
Consider whether both of you can consent to the process, or whether one partner feels ‘dragged along.’ Listen to what your partner needs, and negotiate with care.
Connect with others
If you and your partner are weighing ENM, talk to people who practice it and can explain how it works for them.
Their views and advice can help you decide whether it is right for you.
Manage new relationship energy (NRE)
New Relationship Energy (NRE) is a concept often discussed in the context of ENM and polyamory, though it applies to all types of relationships.
It is that giddy, excited feeling you get when things are going well with a new relationship.
However, NRE is temporary and you should be mindful of this when practicing ENM.
“Enjoying that satisfying feeling [of NRE] is perfectly fine, but it can come with some unintended side-effects. Make sure you’re not chasing NRE only to abandon people when the feeling inevitably wears off or at least diminishes.”
Check-in with each other
Whilst engaging in ENM, ensure you check in with your partner regularly.
Make sure they are still consenting to the relationship style and whether there is anything to work on or other boundaries to be put in place.
Consent is ongoing. Research on couples in treatment finds that an arrangement’s success depends on partners continuing to practice honesty, not merely agreeing once (Watstein, 2022).
Frequently Asked Questions
Can ethically non-monogamous people get jealous?
While ENM people can get jealous, many who practice ENM believe monogamous relationships can often be filled with more jealousy or possessive feelings.
ENM often involves letting go of extreme jealous feelings and instead learning to be happy that your partner is doing something which makes them happy.
Many believe jealousy is a useful emotion as it gives people a chance to learn about what they need to feel secure.
Some people who are ENM may get jealous while others do not – what matters is how jealousy is handled and ensuring boundaries are in place to manage this.
Are there any limits to a non-monogamous relationship?
Every relationship is unique in its own way. Boundaries can differ from one relationship to the next, so what might be ok in one relationship may not be ok in the next.
It is up to each partner to communicate their desires and limits, with those limits being respected.
Can ethical non-monogamy be sustainable?
Many people practice ENM for years or longer if this is what all parties involved want.
Research finds no satisfaction penalty. A 2025 meta-analysis pooled 35 studies and more than 24,000 participants. It found no significant difference between monogamous and consensually non-monogamous samples in relationship or sexual satisfaction (Anderson et al., 2025). Exclusivity alone does not make a relationship satisfying.
Making time for self-reflection, having realistic expectations, and checking in with your partners can help to ensure the relationships last.
Exploring ENM does not mean you can never return to a monogamous lifestyle. It is possible to be ENM for a short amount of time, then return to being exclusive to one person.
It could be that one person will want to return to monogamy. In contrast, the other wants to stay ENM. These differences can and do sometimes mean that the relationship needs to come to an end, as they can with other types of disagreements not limited to relationship structure.
How can you bring up ethical non-monogamy to a partner?
Consider whether the interest in ENM is equally shared and whether you have the communication skills to broach the subject in a gentle way that still reassures your partner.
Considerate, non-judgmental sharing and listening are usually key.
Whatever the nature of the relationships, it is essential to talk about boundaries and expectations, including those related to shared space, allocated time, and acceptable behavior.
What is the difference between polyamory and ethical non-monogamy?
ENM is an umbrella term for many types of relationship structures, and polyamory is just one way to practice it.
Polyamory refers to having multiple romantic or intimate relationships at the same time, whereas ENM is any arrangement where people have multiple consensual romantic or sexual connections.
Research on Ethical Non-Monogamy
A growing body of research looks at how people practicing ENM actually fare, and at what happens when ENM meets institutions built around a single-partner assumption. The most recent work spans direct outcome studies and applied research on healthcare and therapy.
Relationship Quality Compared With Monogamy
Gupta and colleagues reviewed 209 published studies on polyamory and consensual non-monogamy for a wide-ranging scoping review. They coded each study for research design, theoretical framework, and findings, sorting the literature into seven broad domains (Gupta et al., 2023).
The seven domains were:
- Outcomes of CNM relationships
- Attitudes and perceptions of CNM
- Antecedents of CNM (what leads people to it)
- CNM relational processes
- CNM identity development
- Polyamorous family and parenting
- CNM politics and discourse
Within the outcomes domain, one picture emerged. People practicing consensual non-monogamy reported relationship satisfaction, psychological wellbeing, and relational functioning broadly comparable to monogamous comparison groups.
That does not mean every relationship structure works identically. What differs most consistently across monogamy, open relationships, polyamory, and swinging is not psychological wellbeing, but the specific practice a couple has actually agreed to.
A 2025 meta-analysis points the same way. It pooled 35 studies and more than 24,000 participants, comparing monogamous and consensually non-monogamous samples.
It found no statistically significant difference in either relationship satisfaction or sexual satisfaction (Anderson et al., 2025). That counters the assumption that exclusivity is what makes a relationship satisfying.
The scoping review carries one clear limitation.
Most outcome studies rely on people who already identify comfortably as non-monogamous to a researcher. That likely excludes people practicing it privately, or without a settled label (Gupta et al., 2023).
Stigma in Healthcare and Therapy
Stigma toward ENM extends beyond friends and family.
Campbell and colleagues surveyed and interviewed 67 consensually non-monogamous adults about their trust in healthcare professionals and their disclosure decisions (Campbell et al., 2023).
Three findings stood out:
- Lower trust: Participants reported significantly lower trust in healthcare professionals than standard comparison scores.
- Mostly disclosed: Sixty-three percent disclosed their relationship structure when accessing sexual healthcare.
- Often concealed: Thirty-seven percent sometimes or never did, often to avoid anticipated judgment.
The gap was stark.
That matters because an inaccurate sexual history can affect testing and care decisions (Campbell et al., 2023).
The authors read this as a training gap, not a patient problem.
Clinicians need the skills to take an accurate history without moralizing about partner numbers or defaulting to guidance written only for monogamous patients.
Therapy carries the same pattern. A UK study of 19 consensually non-monogamous adults found that mono-normativity operates on both sides of the room. Clients anticipate judgment. Some practitioners treat the relationship structure itself as something to correct, rather than a legitimate choice (Swindlehurst et al., 2023).
Both research teams recommend dedicated training for clinicians and therapists working with consensually non-monogamous clients, rather than leaving patients to manage the stigma alone. Neither study followed clients over time to test whether such training actually changes outcomes, a natural next step for future research.
One caution applies to the healthcare study too. Its 67 participants already identified openly as consensually non-monogamous, so it likely under-represents people who struggle most with disclosure.
Further Information
What Relationship Experts Say
Esther Perel is a couples therapist and host of the podcast Where Should We Begin? She says polyamory now comes up in nearly every professional conversation she has about sexuality and monogamy.
Polyamory as Distributed Roles, Not Commitment Avoidance
As Perel explains, polyamory is a form of consensual non-monogamy marked by emotional, and often romantic, attachment on top of any sexual involvement.
That sets it apart from purely sexual arrangements.
Perel directly challenges the idea that polyamory reflects an inability to commit. Sustaining several conscious, negotiated relationships, she argues, takes more communication and effort than a single relationship, not less.
Perel also points to four features of polyamory in practice:
- Outsourcing: Perel describes polyamory as emotional “outsourcing.” Rather than one partner being best friend, co-parent, and ideal sexual partner at once, roles spread across relationships.
- Time to talk: Perel notes a running joke among polyamorous people: the arrangement only works if everyone has plenty of time to talk things through.
- Community: According to Perel, polyamorous people tend to be closely networked, with their own conferences, support groups, and shared parenting arrangements.
- History: Perel traces organized polyamorous communities to the United States in the 1800s, with a further resurgence from the late 1960s sexual revolution.
When “Ethical” Breaks Down
Perel also works through cases where the “ethical” half of ethical non-monogamy fails in practice. Take one caller’s case. She believed, for two years, that she was in a consensual polyamorous relationship.
It was not. Her partner’s other partner had never been told about, or agreed to, the relationship at all.
Perel told the caller she had “kept her compass” throughout, even while being deliberately misled. As Perel frames it, what separates ethical non-monogamy from infidelity is not how many people are involved. It is whether everyone affected genuinely knows, and has consented.
A relationship described using the language of polyamory can still function as concealed cheating, in Perel’s reading, if that consent was never real. That is the whole distinction the word “ethical” is doing.
References
Anderson, J. R., Hinton, J. D. X., Bondarchuk-McLaughlin, A., Rosa, S., Tan, K. J., & Moor, L. (2025). Countering the monogamy-superiority myth: A meta-analysis of the differences in relationship satisfaction and sexual satisfaction as a function of relationship orientation. The Journal of Sex Research, 63(1), 130–142. https://doi.org/10.1080/00224499.2025.2462988
Campbell, C., Scoats, R., & Wignall, L. (2023). “Oh! How modern! And… are you ok with that?”: Consensually non-monogamous people’s experiences when accessing sexual health care. The Journal of Sex Research, 61(9), 1377–1388. https://doi.org/10.1080/00224499.2023.2246464
Conley, T. D., Moors, A. C., Matsick, J. L., & Ziegler, A. (2013). The fewer the merrier?: Assessing stigma surrounding consensually non-monogamous romantic relationships. Analyses of Social Issues and Public Policy, 13(1), 1–30. https://doi.org/10.1111/j.1530-2415.2012.01286.x
Gupta, S., Tarantino, M., & Sanner, C. (2023). A scoping review of research on polyamory and consensual non-monogamy: Implications for a more inclusive family science. Journal of Family Theory & Review, 16(2), 151–190. https://doi.org/10.1111/jftr.12546
Haupert, M. L., Gesselman, A. N., Moors, A. C., Fisher, H. E., & Garcia, J. R. (2017). Prevalence of experiences with consensual nonmonogamous relationships: Findings from two national samples of single Americans. Journal of Sex & Marital Therapy, 43(5), 424–440. https://doi.org/10.1080/0092623X.2016.1178675
Heath, M., Braimoh, J., & Gouweloos, J. (2016). Judging women’s sexual agency: Contemporary sex wars in the legal terrain of prostitution and polygamy. Signs: Journal of Women in Culture and Society, 42(1), 199–225. https://doi.org/10.1086/686771
Scipione, K. J. (2021). A qualitative exploration of consensual non-monogamy relationships between married heterosexual couples [Doctoral dissertation, California Southern University].
Swindlehurst, S., Sweet, J., & Hoelterhoff, M. (2023). Room for growth: A qualitative study into the therapeutic experiences of consensually non-monogamous clients in the United Kingdom. Journal of Couple & Relationship Therapy, 23(2), 115–138. https://doi.org/10.1080/15332691.2023.2294856
Watstein, T. (2022). Therapeutic Considerations for the Polycule: A Qualitative Exploration of Consensual Non-Monogamy in Couples Treatment.
Wood, J., De Santis, C., Desmarais, S., & Milhausen, R. (2021). Motivations for engaging in consensually non-monogamous relationships. Archives of Sexual Behavior, 50(4), 1253–1272. https://doi.org/10.1007/s10508-020-01873-x
