I think your judgement of this girl sounds spot on from what you describe of her behavior. I'm sure you've already told him all of this-I would suggest that you suggest that he get some counseling for his own benefit&maybe add that you're really concerned about him&the behavior that he's putting up with. I know what it's like to love&not be loved back. IT HURTS!!! And it's hard to let go-but for his own sake he needs to. He hasn't become suicidal over this girl's rejection of him has he? If he has or does, definitely get him some help even if it means taking him to the ER. Hope for the best for you&your friend-hope things can work out.