I think you have done as much as you could and you have to leave it at that. It's ultimately his decision and if he is "in love" it's going to be hard to tell him otherwise. You've been a good friend by respectfully showing your concern, if you went any further, you might risk the friendship.
i agree. pushing the issue will only put a strain on your friendship. As frustrating as it is, from exp. i know the best thing to do is just be there to support him no matter what. and he's going to need you when reality hits.