I'm 100% with shortandcute. Just because your friends have a different opinion than the majority of the people who are answering you on here doesn't make that opinion correct, it just means that birds of a feather flock together. And perhaps that your friends are telling you what you want to hear and not what you need to hear, because unfortunately a lot of friendships between women are like that--we feel like it's more important to be liked by our friends than to give them good advice. You asked a question, several people gave you basically the same answer, and yet this thread is on its third page. I'm confused as to what more you're looking for. I am honestly not trying to be mean to you. But the long and short of it is that this guy is not respectable, if he were he wouldn't be chatting you up like he was interested in something with you while he has a girlfriend regardless of the situation with said girlfriend. Proceed however you wish (because you're going to anyway), but don't be surprised when things don't turn out so good for you because it doesn't really sound like he respects either you or the woman he's with. There are plenty of other men to chat with, and both of you (women) deserve better. And it makes me sad that you don't already know this.