Just tell him you're going to wait to see if he's successful and then sue him and take half of it. That should bring him back to the discussion table ;-) Reall

Just tell him you're going to wait to see if he's successful and then sue him and take half of it. That should bring him back to the discussion table ;-) Really though you guys need to sign a legal agreement dissolving the partnership and specifying who owns what. Otherwise neither of you can re-use any of the existing IP safely.