I get excited over ruining, peoples relationships?

This does sound like a big problem if you get your kicks out of destroying other peoples relationships, it also sounds like you've lost respect for women. I suggest you start dating women with some morals and not some slag whose going to drop her knickers for any guy with a six pack, at the end of the day having a one night stand with a tart isnt really much of an achievement, and she certainly will not be a girl who you would want to settle down with.