Wow... so many MIL posts today! Wierd. I had my MIL incident last week!!
It's so true that alcoholism is a family disease. It's is a horrendously awful disease... like a tornado... that destroys everyone in its path. Leaving behind torn, twisted and battered souls.
I came from a dry drunk home with a full on raging, co-dependent mother who insisted ultimatums made the world go 'round. AH came from an alcoholic father, and a raging co-dependent mother who also worshipped the ultimatum gods.
Funny, because when we met - people always said I was just like his mom, and he was like my dad. And cycle continues...
well, until I found Al-anon and became hell-bent on changing the game.
My best advice - interact with family (his and yours) with the same methods you would use with AH. The tools we learn in al-anon can be applied to all aspects of our lives!