I'm just going to be blunt and probably make a few angry. Wouldn't be the first time, LOL!!
Kick his butt out! It's time for him to move on. Sit him down, tell him that this is your house and give him a timeline on how much longer he has allowed to stay with you. He doesn't have to do for himself because he doesn't have to. He probably will resent you for awhile but it's all just a part of parenting in my eyes. I don't have all the answers for sure...Never will say I do.
Again, I apololgize for writing what I feel. I understand that my thoughts are harsh and seem unfair or mean.