There are many types of non-monogamous people and relationships, and they can take many forms. There are single people who are not sexually or romantically exclusive to one person, polygamists, polyamorous and “monogamish” relationships, those who are in a committed relationship but are open to other sexual or romantic partners, and those who cheat.

The difference is that a person who cheats is not in an open relationship based on “ethical”1 or “consensual non-monogamy” (CNM).2

CNM relationships may or may not be like “monogamish”3 or open relationships, in which otherwise committed people dedicated to one another through marriage or otherwise share a life together without sexual or romantic exclusivity.

In an open “monogamish” or CNM relationship, both partners in a committed relationship are open to and agree on the terms for either both or just one partner pursuing sexual or romantic relationships with other consenting people. Open relationships or CNM include, but are not limited to: open marriages; swinging; cuckolding; polyamorous relationships (click here for the Polyamory Topic on, and polygamy (click here for the Polygamy sub-topic in the Multiple Marriages Topic on

Some CNM and open relationships may seem similar or some terms may seem synonymous, but they may be different. “CNM [consensual non-monogamy] ranges from polygamy and polyamory on the serious, long term relationship end of the spectrum, to open, monogamish, or swinging relationships that may have more emphasis on sexual variety and less emphasis on emotional intimacy with multiple partners on the other.”4

People who have sex with friends, known as friends with benefits or f*ck buddies, may be in an open relationship5 but generally not in a sexually or romantically exclusive relationship with one another and are engaging more in consensual non-monogamous casual sex (click here for the Casual Sex Topic on

“Now, new findings from Kinsey show that over 20% of people surveyed have had open sexual relationships in their lifetimes; that is, relationships with an agreed-upon, sexually non-exclusive component… On the other hand, the researchers did find differences in having consensual non-monogamous relationships based on gender and sexual orientation. They found that men were more likely to have ever had a consensual non-monogamous relationship than women. Additionally, people identifying as gay, lesbian, and bisexual were also more likely to have ever engaged in a consensual non-monogamous relationship than those identifying as heterosexual.”6

“A new University of Guelph study has revealed that people in open relationships are as happy as their coupled-up counterparts.”7

Open, consensual non-monogamous relationships are not for everyone. Some people may use this type of relationship to cover up other problems,8 one person may be more open to it than the other who just chooses to go along to please their partner9 or someone gets jealous,10 and some people in open relationships have faced scrutiny and workplace discrimination.11

Defining what is and is not acceptable, from safe sex practices to level of romantic attachment to sex acts, is necessary for navigating a consensual non-monogamous open relationship,12 but the myriad types of relationship configurations may defy labels.13 

The seven sub-topics below provide more information on the different forms of non-monogamy practiced by consenting adults in open, but committed, relationships.

  1. Cuckolding Click here
  2. Open Marriages Click here
  3. Open Relationships Click here
  4. Polyamory (opens to the Topic from the SexEd menu)
  5. Polygamy (opens to the Topic from the SexEd menu)
  6. Swingers Click here
  7. Unicorns Click here



1., 4/15/2015

2., 4/26/2017

3. term by Dan Savage, Host of Savage Lovecast, several sources, accessed 9/22/2018

4., 8/10/2016 

5., 11/21/2016

6., 6/5/2018

7., 6/5/2018

8., 6/1/2018

9., 3/21/2017

10., 11/8/2017

11., 10/10/2017

12., 8/10/2016

13., 3/15/2017