Oh Bean...I'm so sorry babe. I can't even imagine frankly. Ick. But I know you realize you can't control it so that just leaves you with acceptance. Acceptance that you can't control it...not that his behavior is ok.
He's just digging his own grave with your S by shoving this down his throat. Selfish SOB. Blech. But as Ian said, as long as he has you as his compass he'll be ok. Teach him right from wrong, validate his feelings, teach him acceptance and love...its all you can do and its all he needs.
But I know you realize you can't control it so that just leaves you with acceptance. Acceptance that you can't control it...not that his behavior is ok. 
