Even though men have beautiful lovers, girlfriends or wives, they will cheat if they feel they are not getting what they want out of the relationship. That is one reason. The other reason is that they enjoy sex with other woman...period! If they can get away with it, they will do it and it excites them. It is as simple as that. The only reason a man would not have sex with other woman but his wife, is if he truly is dedicated to his woman and does not ever want to hurt her. He may still have desires to be with another woman, but he would prefer to keep his marriage safe rather than engage in his fantasies.
It's not about the looks all the time. It's about the feelings that the cheater has inside (unhappiness, anger, etc). That's not to justify cheating, but I say it to point out that looks often don't have anything to do with it. I have a friend who has a very attractive gf, and she is very nice. My friend has at least two women on the side. I've asked him what's the deal with that, and I STILL don't understand why. I don't think HE understands why. I think it's about opportunity. He sees it, and he pounces on it. That's the best that I can come up with that seems to make some sense.
Definitely looks have nothing to do with it - see Halle Berry, Christie Brinkley, etc. Beautiful women get cheated on all the time. If a man is unhappy in his relationship, he should just end it and move on, but they tend to want their cake and eat it too. A new woman in his life makes him feel better about himself, that's all, and not even for very long, but enough to get him out of his funk of "she doesn't appreciate me".
Got something to say about it? Read the original article and all the comments here.