The Most Common Affair Partner For Married Women May Surprise You, Says Research
Research suggests that women are more likely than men to pursue same-sex partners while in a committed marriage, a trend experts attribute to sexual fluidity rather than a fixed change in sexual orientation. While the phenomenon is complex, studies indicate that women often show a greater willingness to update their sexual identities throughout their lives compared to men, who typically maintain a more consistent orientation.
Understanding Sexual Fluidity
The concept of sexual fluidity, coined by psychologist Lisa Diamond in 2008, describes the capacity for individuals to shift their sexual attractions or identities over time. Following a decade-long study of 100 women, Diamond found that sexual fluidity is distinct from bisexuality. While bisexuality implies a sustained attraction to both genders, fluidity involves the potential for a person to make exceptions to or fundamentally update their identity based on changing circumstances.
Psychophysiologist and neuroscientist Nicole Prause notes that data supports the idea that women are more likely to change their reported sexual orientation depending on their environment. In contrast, Prause explains that men appear more resistant to altering their identity based on intimate behavior alone.
Biological and Social Drivers
Experts are examining whether hormonal or social factors drive these shifts in relationship patterns. Sheryl Kingsberg, a professor of behavioral medicine at University Hospitals Cleveland Medical Center, has observed a mild increase in women in their 30s transitioning toward same-sex relationships. Kingsberg suggests this could be linked to neuroendocrine or epigenetic shifts in brain chemistry.

Other theories focus on testosterone levels, which have been linked to an increased incidence of homosexuality and bisexuality in women as they age. However, clinical social worker Alisha Powell emphasizes that social factors play a major role. Powell suggests that while men may possess the same potential for fluidity as women, societal stigma often prevents them from acting on it. In many Western societies, women currently face fewer social costs for engaging in same-sex relationships than men do.
What Happens Next
As researchers continue to study these patterns, it is likely that the conversation surrounding marital infidelity will shift to include more nuanced discussions about identity. If social stigma toward male fluidity continues to decrease, analysts expect that reported rates of sexual fluidity among men may eventually rise to mirror those seen in women. In the short term, relationship counselors may increasingly encounter couples navigating these shifts, with experts noting that fluidity is rarely the sole cause of a divorce, but rather one factor among deeper, existing relationship issues.
Frequently Asked Questions
Is sexual fluidity the same as being bisexual?
No. According to research by Lisa Diamond, bisexuality is a defined attraction to both men and women, whereas sexual fluidity refers to the capacity to update or make exceptions to one’s sexual identity over time.

Are women more likely to cheat than men?
The research does not suggest that women are more likely to cheat than men. Instead, it indicates that when women do engage in infidelity, they are more likely to do so with a same-sex partner due to a greater capacity for sexual fluidity.
Is this trend primarily biological?
While some experts like Sheryl Kingsberg point to potential hormonal or neuroendocrine shifts, many researchers believe the trend is primarily a social phenomenon, noting that women currently face fewer social consequences for same-sex relationships than men.
How do you think evolving social norms will continue to influence how people define their sexual identities within long-term marriages?