Thats an awful lot of attention he's getting for his sulking.

Might not seem the most helpful comment but its the thing that jumps out at me, that his behaviour is getting him results. Perhaps time to keep meetings and appointments seperate from him and get on with your day with his behaviour taking as little effect as possible. However having said that if he doesn't realise how his behaviour affects others then take the bullying seriously because from his point of view thats what it is...and noone should be hitting him regardless, there are ALWAYS other options.