The impression that I got from this is someone basically saying "well, when it all comes back to you, i'll get revenge for how you make me feel". It's all about losing trust in someone you thought you could rely on ("I thought you were a good man"), obviously because you don't really think this kind of thing could happen. And angelsamongus, just because someone can't forgive another for this doesn't make them a bad person. Living with this type of thing hurts. You don't forgive. You just try to forget. I'm inclined to agree with the latter two sentences from ladyofshadows in this case.