Straight Men Care Less About Cheating, if It Happens for This Reason: Study

For many, infidelity is deal-breaker. But perhaps not always for men partnered with women who like women.

A study published February 21 in the journal Personal Relationships found that heterosexual men reported less "distress" about infidelity when it involved their female partners being with other women. The reason for this, the paper said, is that men may perceive the third woman to be a potential sexual opportunity.

"Heterosexual men report less distress at infidelity from female interlopers than male interlopers…men could also perceive these women as additional sexual opportunities if they assume mutual interest from the female interloper," the authors wrote.

Two studies were conducted to arrive at the findings. The first examined how the "sex role presentation"—either masculine or feminine—of a third party affects heterosexual men's reactions to infidelity. This was tested among 156 men from a large public university and involved three written scenarios describing the experience of finding a long-term girlfriend being intimate with someone else: a man, a more masculine woman or a more feminine woman.

The second study mimicked the first, but this time with stock images of the hypothetical girlfriend and third man or woman. In both studies, the findings looked similar: Heterosexual men consistently had the most negative reaction to infidelity involving another man as the third party. Conversely, they exhibited significantly less distress when the third party was another woman—especially a more feminine-presenting woman.

Men saw greater sexual opportunity in the more feminine women, consequently lowering their distress, the study found. Men largely assumed the more feminine woman to be bisexual, the masculine-presenting woman to be primarily homosexual and the man to be primarily heterosexual.

Study caveats and future research

Author Mitch Brown, an instructor of psychological science at the University of Arkansas, told PsyPost that the idea for the study came from a conversation with an undergraduate student.

"The topic started out as a discussion with one of my undergrads back in grad school about how sex role presentation may influence reactions to infidelity seen in various papers covering same-sex infidelity," he said.

"My student and I were considering the fact that such reactions could have multiple causes that would manifest in different ways. Namely, does the reduced risk of cuckoldry from a female interloper in a man's relationship coincide with perceptions of the interloper as an additional sexual opportunity? If so, when does that actually happen?" he said.

Within his study, however, there is room for nuance. Brown said that accounting for different relationship structures—like consensual nonmonogamy—could lead to different findings where men find intimacy outside of the primary relationship more tolerable.

Brown said there is definitely room for more research beyond these findings.

"Perceptions of the sexual interest of the interloper in these studies were based on stereotypes," he told PsyPost. Future research, he said, might include information about the interlopers' actual sexual orientation to eliminate the influence of stereotyping urges.