Quote of the Day
For heterosexuals, rates of infidelity are four times higher than the rate of open relationships. By contrast, for sexual minorities (with the exception of lesbians), rates of open relationships are higher than the rate of infidelity.
Justin Lehmiller @JustinLehmiller
Posted on X, March 7, 2026
See also Rates of Consensual and Nonconsensual Nonmonogamy Among Heterosexual, Gay, and Bisexual Adults – Sex and Psychology. This article gives us the numbers:
- Overall prevalence of infidelity: about 8% of heterosexual participants, 14% of gay participants, 6% of lesbian participants, 18% of bisexual participants, and 6% of those who described “other” sexualities reported nonconsensual nonmonogamy (defined here as agreeing to be sexually exclusive with a partner, but one or both partners cheated or had an affair).
- Overall prevalence of open relationships: 2% of heterosexual participants, 32% of gay participants, 5% of lesbian participants, 22% of bisexual participants, and 14% of those who reported “other” sexualities.
The way I initially read the post on X was that open relationships result in lower the rates of infidelity. But reading the article I find that even with a higher prevalence open relationship as sort of a “safety valve” the infidelity rates are actually higher.
I’m not sure what to conclude about this other than, “That’s interesting.”
The data suggest that men are far more likely to stray than women, which evolutionarily speaking makes sense. But it doesn’t say so explicitly. The missing data point: for man/women couples, which partner(s) cheated?
Pure biology and evolution on display. Men make billions of sperm at little physical or emotional cost to them. The best survival strategy for your genes is to spread your seed far and wide as often as possible
This maximizes the chances of your genes being passed along to the next generation in a pre-industrial world (nearly all of human history). For women the biological imperatives are quite different because they have a severely limited number of times they can become pregnant and carry a healthy baby to term and get them through the years long vulnerable period of infancy. By the time a child is five or six years old they’ve probably been exposed to the common diseases and will survive to reproductive age. In order to maximize the chances of their genes being spread to the next generation they want to select the best mate (sperm donation) available and then select a husband or support group who provide the best possible home to raise their children in. Throughout most of human existence this means secure and wealthy. Please note; optimal selection for the sperm donation and husband function often DO NOT coincide! Hence the prehistoric foundation of “the Patriarchy” as long term providers of security and wealth attempt to ensure they are providing these very expensive materials and services to their own progeny and not to the child of some alpha male jock… handsome muscle bound hunter who stopped off at the tribe for a day or two to trade pelts and obsidian arrow heads.
“I’m not sure what to conclude about this other than, “That’s interesting.””
My conclusion would be “whoever pushed this do so dishonestly to get the sort of headline they wanted”, as the definite implications of their wording was just plain false.
The nicest interpretation I can come up with would be that “non-traditional” types don’t receive societal support in their relationships and thus have higher rates of such things.
I’m quite confident that, while there may be at least some aspect of that, the truth is much… less nice.
The more realist part of me points out that, without the possibility of children from the activity, there is one less inhibitor of such behaviour (also seen in the MUCH higher rates of open relationships), and that is one of the stronger inhibitors, so…
The jaded part of me points out that many people in that “lifestyle” have fully turned their back on society in terms of giving back and are living entirely for their own pleasure (also as seen by the higher rates of open relationships). Sex is something to be consumed, nothing more. Such results are thus not surprising.
Probably at least some truth in all 3, I think.
People with certain types of neurodivergence and/or certain mental health issues are WAY more likely than everyone else to self-identify as bisexual, and also more likely to be non-monogamous. Sometimes these are the same people & sometimes not, but it’s a thing.
I have a theory that (a) they are more honest about it—if you’re weird in so many other ways, why not add another one to the list? And/or (b) they are more likely to know/find out “oh, that’s what that is” while in therapy for something else, and/or they are higher in trait openness vs. the mean, and/or it just kind of comes with the territory.
I think people like to fuck.
Just a guess.
Can’t believe ANYTHING you read about people’s ‘sex lives’. Because they lie about it. Either they are ashamed and won’t admit to many things or they overstate and inflate things because of braggadocio. It’s simply NOT a subject that lends itself to accurate large scale study.
I wonder if there’s a disparity in how different couples define “open relationship,” and/or differences in how people in such relationships define “infidelity,” and if the researchers took that into consideration.
To clarify*: Does “open relationship” mean either partner can have sex with whomever they desire and it’s not considered infidelity? Or does it mean sex outside their relationship with their spouse/partner is allowed as long as it’s disclosed or approved — and considered infidelity only if it’s kept secret? Or do both spouses/partners need to be involved with this hypothetical third-party for it to be sanctioned (i.e. threesomes are okay, but twosomes with third-parties are not)? Or no-strings sex is okay but outside emotional relationships are not, or vice versa?
Like many things, relationships are built on rules, and rules require definitions. Those rules and definitions can vary widely from person to person or couple to couple, but can still fall under the umbrella of a single term such as “open relationship” or “infidelity.”
So my question, in effect, is whether “open relationships” among heterosexuals prevent/mitigate “infidelity” by keeping one’s acceptable sexual options open (IOW, people in non-open relationships cheat more by stepping outside their relationship rules), or whether “open relationships” among heterosexuals contribute to “infidelity” by people being unclear on, pushing, or willfully violating the rules of their relationships.
Or is it an overall wash because both are true?
It is indeed interesting.
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* – I have personally known couples in “open relationships” with all of these rule variants and definitions of “cheating” (i.e. infidelity). I even knew one couple where the specific rule was, sex with outside third-parties was fine with condoms, and cheating without, with the exception of female-on-female (she was bi).