long story short I have a friend whom I've been fooling around with on and off for about a year up until last month. We decided to cool off, stay friends, and see other people. The both of us did just that and now he's callin me back telling me how much he misses me. The only problem is he recently called things off with one of my close co-workers & she was really hurt by it. My question is, should I go ahead & have sex with the guy even though I know how bad it would hurt my co-worker? I mean, it's not like they were officially dating or anything...