Is somebody going to drop in and check to make sure no parties or anything you and he both know shouldnt happen wont be going on? I would be worried about that. Even very nice adults with an empty house throw parties that can turn drunken and cause home damage and fights.
Promises are just pretty words.
in my opinion it would be good if somebody checked regularly. I would not have left even my best behaved kid alone for two months although she never got into any trouble and is now in law enforcement.
