Ethical non-monogamy

Also: ENM, consensual non-monogamy, CNM

An umbrella term for relationship structures in which everyone involved knows about, and consents to, the participants having more than one romantic or sexual connection.

1 min read · Reviewed 2026-05-20

Ethical non-monogamy (ENM) is the umbrella term that covers every relationship configuration in which the people involved are honest with each other about the existence of multiple romantic or sexual partners. The word ethical here is doing all of the work: it is not a moral grade, it is a description. The distinguishing feature is informed, ongoing consent from everyone affected. A relationship can be ethical and non-monogamous; a relationship can also be unethical and non-monogamous, in which case it is more usually called cheating.

ENM is not a single relationship style. It is a category. Underneath it sit polyamory, open relationships, relationship anarchy, solo polyamory, kitchen-table polyamory, parallel polyamory, monogamish arrangements, polyfidelity, and a long list of other configurations. The category exists because all of these structures share one premise — multiple connections, openly negotiated — even though they differ sharply in how the connections are structured, prioritised, and described.

Two synonyms appear frequently. Consensual non-monogamy (CNM) is the term most often used in academic writing; some researchers prefer it because it foregrounds the consent dimension and avoids the loaded word ethical. The two terms are used interchangeably in practice. Some practitioners use just 'non-monogamy' for short, dropping the qualifier once context is established.

Survey data suggests ENM is more common than the cultural conversation implies. A 2016 study by Haupert and colleagues, drawing on two nationally representative US samples, found that around 21% of single adults had practised some form of consensual non-monogamy at some point in their lives. Subsequent surveys have produced numbers in similar ranges across different populations.

What ENM is not: it is not cheating renamed, it is not a phase universally outgrown, it is not synonymous with promiscuity, and it is not the absence of commitment. Practitioners in long-term polyamorous structures often describe the level of communication required as higher than they experienced in monogamous relationships, not lower.

Where this term fits in the wider picture

Ethical non-monogamy is a network of overlapping practices, identities, and structures — and Ethical non-monogamy connects to several of them. The neighbouring terms below show how this one sits alongside the rest of the vocabulary practitioners actually use; the guide at the end is the longer-form treatment of the same territory.

Closely-related vocabulary

Polyamory
The practice of, or willingness to engage in, multiple loving romantic relationships, with the knowledge and consent of everyone involved.
Open relationship
A committed primary relationship in which the partners have agreed that outside sexual, and sometimes romantic, connections are allowed within negotiated terms.
Relationship anarchy
An approach to relationships that rejects ranked hierarchies, prescriptive escalator scripts, and the assumption that romantic relationships should be valued above platonic ones.
Monogamish
A largely-monogamous relationship that has agreed-on, often narrow, exceptions to strict exclusivity — typically rare, usually sexual, often situational.

Questions practitioners actually ask about this

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The longer treatment of this territory is in the guide What is ethical non-monogamy? A clear primer for adults thinking it through — An honest, plain-language introduction to ethical non-monogamy — what it is, what it isn't, the configurations it covers, and the questions it asks of you.

New to ethical non-monogamy? Start with the glossary for vocabulary, the structures index for the named relationship configurations practitioners actually use, and the guides for longer-form treatment of the common questions.