@Trying To Be,
Here is a piece of advice I got off another site. This makes sense to me.
Your gf is right when she says that she should have been very direct with him from the very beginning and maybe this would have been avoided.
Aside from that, as far you feeling as if maybe she was receptive in a sense, maybe not. Some people are very persistent in their approach and everything but an exact hell no is a piece of hope for them. Some people just don't respect others relationships and it seems to be the issue with this guy. With that being said, your gf should have respected your wishes and once she seen that the friendship wasn't innocent on his part, she should have ended it out of respect for you. But it's over now so if talking to him makes you feel better then do it but what are you going to be getting out of it other then what she told you? If you have trust issues about what happened then your problem is really with her and you need to talk this over with her because you can't really expect too much out of a guy that didn't respect your relationship with her in the first place. If the circumstances was different, he'd still be pushing up on her. Voice your concerns with her and see how the trust can be put back into place, if at all.