Thanks to everyone else (pretty much) for their words of support. It's a really awful situation that I can't do anything about. I'm fairly sure he knows although I haven't flat-out told him, and he doesnt seem to be any different around me; I think he just sort of accepts it.
In some ways, that's worse; I would rather like him to care somewhat, either in a good or bad way...
I know there will be comments like "Hey, at least he's still your friend" and stuff, and whilst I do appreciate that, it's kinda depressing