Thanks everyone. I really do appreciate you sharing your thoughts and experiences.
I guess what I'm wondering most is if anyone knows how much right I really have to restrict access. He's never been caught drinking and driving, but I know if he "falls off" he will drive with them. I'm not okay at this point with him seeing the kids alone because I can't trust that they are safe. I've been letting him visit here (he plays with younger son downstairs) but I don't think that's healthy for me anymore...wondering if he's drinking, trying see if he's acting drunk or hung over. Does that make sense?