Are you kidding? Go for it!! Your big mistake was talking to her for 45 mins??? You guys already had one foot in the bed, at that point. You don't like this guy but you honor his, what, feelings?? That makes it even better cuz he's an ass. Probably others think he's an ass too, including Ms. Hottie. The sex will be great cuz of this. You know that. It would have been even hotter sex if he was your BFF...not that it would be OK or right, just sayin...She made the move, not you. Be a man, take one for your team.