Ok so there's this girl I know and we're not really friends but we don't have anything against eachother. We were talking one day about her boyfriend and she admitted to me that she cheats on him all the time and doesn't feel bad about it at all. And I was thinking "ok whatever". Then a couple weeks later I was at a party and they were there. Long story short I kissed her boyfriend and she got her panties in a twist. I thought that was ridiculous because if she cheats why should she care? Since then her boyfriend and I have kissed (nothing else) a couple of times when she wasn't around. I'm really thinking about hooking up with him. So should I feel bad about that? Should I not do it?