I can totally understand where you're coming from. I'm a pretty vengeful person myself and it really is satisfying when someone gets the payback they deserve.

But, as I get older, I'm starting to realize that revenge just isn't worth it. But if you truly want to hurt/piss her off, then go ahead. I think in this situation, the best revenge would be to find someone else who loves you and let her see how much happier you are; with them rather than her. Girls can't stand that crap.