I realise this is a fairly simplistic explanation, but I suggest you read up onThe Ladder Theory. I had exactly the same problem you are having a few years ago, and this theory, as cynical as it seems, really made a lot of sense to me when I read it. It's not that he's better than you; he sounds like a bastard. But his bastardness probably only makes him more attractive to the girl in question, not less so. Happy reading.