I don't think it's anything to do with being a guy or a girl. I think you know anybody could potentially cheat on somebody It really just depends on their characteristics and not necessarily their binary gender. There we go.
The really fucked up thing is why people cheat. Men will cheat for physical reasons the majority of the time. But women will cheat for emotional reasons. And then they'll continue to stay with that dude and just use him while cheating on him.