That sounds really awful to have to deal with. Family stuff is so hard, I'm sorry.

I wouldn't send him a check though. I think that escalates the situation by making what is (sort of?) a relationship/interaction problem into something transactional. I don't know, I could be wrong, but that's my feeling.

How much contact do you have with him now? Can you just cut back slowly, and see him less? When he invites him over, can you just... you know... be unavailable?

I hear you about not being able to be direct, since he won't likely listen to you. It's too bad for him though, as it sounds like he's really screwing up his life and relationships. It seems like people don't change though unless they have to (i.e. unless their life gets so bad that they suddenly wonder, "what am I doing wrong and how do I fix it?") - so maybe cutting off contact with him (and his wife leaving, and him having no where to go) would, in the end, push him to examine his behavior?

Even if it doesn't, it might be best for your own health and sanity...