Is there such a thing is life and marriage after infidelity? Both men and women cheat for a variety of reasonsÑdue to problems in a relationship, or a need for intimacy, or because they have a high sex drive, just to name a few. But when focusing on sex differences aloneÑdifferences based on biologyÑmen and women cheat in different ways. Men are more likely to cheat opportunistically. That is, they cheat more often and with someone who may be less attractive or desirable than their current partner. Women, by comparison, tend to cheat more selectively. Women tend to be more flirtatious, take more risks, and act in sexually provocative ways when they are ovulating. Women are also attracted to more masculine and physically attractive men when ovulating.