Why does a guy stick around when you have different views?

Here's what I mean. A guy whos relationship is definitely on the rocks, is a musician, starts talkin' to you and he has a gf who says that its ok for him to sleep with someone while on the road b/c he's lonely or horny, but that its to be a one time thing....then he hears my standpoint that I'd worry bout a guy being faithful, I'd like to be the only one doing that (if he was dating me), and for many health reasons (STD's, crazed fans popping holes into condoms & then gets pregnant), why does HE stick around? The guy is a distance away from me, is it because I'm a challenge?!? Supposively with that response, along with the fact that I don't sleep around unless I'm at that level with a bf, I'm supposively not "ual." He knows my view doesn't click with him, he knows I'm a cly girl, yet he keeps talking to me. I want to think its because he's not getting the attention from his current gf & is going to break up w/her soon.