@elah24,
Life is about experiences and in that learning. So you've learnt you "can" converse well with the opposite sex finally. That's the lesson in this. You've hidden for too long, don't mistake that for "oh, he likes me, I like him, pfttt about the girlfriend, he's going to dump her anyway". If that occurs, imagine her heart? You don't want to be a part of that.
If he breaks up with her, he has baggage in any event and his heart can't jump over to someone else, it never does and he'll also look at you as, "she" was "ok" with the fact I had a girlfriend, that's not marriage material, she could jump to the next guy as well.
If you look at it without those rose coloured glasses you will see a lot clearer.