Men are found to be more on the side of polygamy than women. As humans, none of us are monogamous anyway, but with the development of society and culture, we have created for ourselves rules and restrictions. They bind our animal instincts into standard norms and prevent a lot of chaos and violence and stuff (also lead to it).
Talking about sex and relationships in such a world, the biological and individual factors have led to a lot of unacceptable (but non-criminal) behaviour such as cheating in a relationship. And with the first line, men might cheat more than women. But what might be the factors involved?
Well, many people are just born liar and it is equally true for women as well. But women cheating is a bigger stigma and shameful than men and this fear leads to women cheating less. Even for the fact that women are biologically supposed to lie as a counter to men’s muscular advantage against each other.