Ethical non-monogamy

Ethical non-monogamy (ENM), also known as consensual non-monogamy (CNM), is an umbrella term for relationships in which all partners give explicit consent to engage in romantic, intimate, and/or sexual relationships with multiple people. Consensual non-monogamy differs from infidelity by the knowledge and consent of those involved.

Varieties
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.

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. 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. 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 characterized 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.

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.

Prevalence
It is estimated that up to 5% of Americans, 2.5% of Canadians, around 3% of Norwegians, and 3.3% of Dutch and Flemish 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. 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.