@lisa1471,
"I think he's a user"
Surely you don't mean 'user of drugs' based on your subject line.
rest assured that this kind of thing happens often enough. the reason why he's doing this won't help you nearly as much as the reason for why you feel bothered by his behaviour.
every day there's 20-year friendships being wasted from one moment to the next for no reason.
You'll feel better when you'll have satisfactorily answered the question "why do you feel bothered by his behaviour, and can't just say, All right, his loss after all."