Whats your reason to cheat? Lets keep aside morality and get down to brass tacks!

@Anonymous that's pretty awful - if you found someone like that, surely the decent, human thing to do would be to break up with your existing partner before you go and pursue that hotter, sexier, or smarter person. Being cheated on can totally screw up a person's ability to trust and their ability to have a healthy, functional, romantic relationship. If you loved someone enough to be with them, the least you can do is spare them that pain and humiliation.