Is it shallow of me to leave ugly men alone if they are the ones who always cheated on me?

I've never been about looks, but it seems like the unattractive ones (I only say they were unattractive because other people told me they thought they were) were the ones who always cheated on me. The couple handsome ones I had were always being stared at by other women and sometimes even approached and flirted with by women in my presence (which I thought was hilarious because they weren't even paying attention to those women) and I never had a cheating problem with them - just other intolerable issues. But, I'm starting to think...maybe "craig b" (YA poster) is right. Maybe people do cheat because they need someone of the opposite sex to tell them that they are special, that they've got it. Almost like a insecurity lift or ego boost. I wonder if that's a shallow move on my part...only going for an attractive man.....??