Despite the loosening of sexual restrictions in recent decades, open relationships and cheating remain highly stigmatized. However, focusing on the problem of cheating distracts us from focusing on the problem of monogamy. Long term sex with just one partner leads to less sexual desire for that partner, regardless of the strength of the emotional relationship.

Those entering into their first serious romantic/sexual relationship are misled into thinking that monogamy is capable of providing a lifetime of sexual fulfillment. They believe that if they truly love their partners, they would not desire sex with others. This, we are told, is because monogamy is healthy, proper, moral and natural. Conversely, anyone challenging this is socially stigmatized. But with 13 million people in 22 countries looking to have a marital affair on Ashley Madison.com alone, it suggests that, for many, monogamy is more of a desire, than practice. This is true of both men and women.

My sociological research, combined with the work of psychologists, biologist, anthropologists, and even endocrinologists, suggests that monogamy is an uneasy fit for human beings. It's a fashionable social expectation, but not a biological desire. This means that there is a gap between what we want sexually and morally. The gap is less noticeable when entering into a relationship. But despite the frequent and intense sex of the honeymoon phase, sexual habituation quickly sets in.

Interestingly, the relentless urge to have sex with someone other than one's lover grows stronger as the emotional strength of the relationship develops. When every cell in their body is craving sex with someone else, monogamy begins to feel like sexual incarceration. But this growing sexual desire does not indicate that one has failed to love their partner. In fact, choosing to stay with one's partner, despite wanting sex with others, suggests that they do love their partners. They simply want sex with someone else to fulfill their sexual desires while keeping their emotional relationship intact. If they failed to love their partners, they would be more likely to leave them, particularly if they do not have kids or a mortgage together.

It is at this point that couples ought to have the social freedom to discuss the various forms of open sexual relationships. But because these more honest forms of loving are culturally condemned, we must either choose to live with the agony of longing for sex with someone else, or cheat -- something which the Internet has made far easier. Conversely, asking for an open relationship is more likely to result in break-up, or at least increased surveillance, so cheating becomes a more viable option for most.

Cheating therefore exits as the only rational choice to have one's emotional and sexual desires met in a culture that stigmatizes open relationships/marriages. Cheating serves as a way to meet sexual desires, with as little disruption to their emotional lives as possible. I don't condone cheating, but I condemn the expectation of monogamy for setting up this conundrum in the first place.

In response to my research (which focuses on men), some choose a moralist stance, arguing that men should not act on their desires, no matter how strong. When confronted with the incontrovertible evidence that sexual frequency and quality dies as a relationship grows, others choose (in heterosexual relationships) a woman-blaming, victim-blaming strategy. Research consistently shows that men want more sex than women, and this places the onus of responsibility on women to meet men's sexual needs. Women are told, often by other women, that they need to put more effort into meeting their husband's desires to prevent them from straying.

Others seem to want to doom those unhappy with monogamy to a life of loneliness, suggesting that if they desire sex with others, they should never enter into relationships in the first place. Still others wish for the family unit to dissolve, simply because one has cheated. In all of these cases, the cultural condition of monogamy fails to serve the family well. All of this "morality" tears families apart.

Few, however, highlight the obvious answer to the dilemma of monogamy and cheating -- sexually open relationships. Here, in an egalitarian manner, a couple reserves emotional fidelity, while structuring in rules for extra-dyadic, recreational sex.