Why is it that women cheat?

my mom recently cheated on my stepdad I guess its understandable since they fight frequently, and the never really enjoy each others company, I'm just trying to understand why nt break up if the relationship isnt working, as opposed to cheating? I know as a guy the reason I would cheat is because a girlfriend is nagging me and untrustworthy, and always giving me crap about what I'm doing or where i going, insecurities would lead me to do something, but for women is it the same? and what is the reason why theyd cheat or why you cheated in the past?