sesh

We're posting in the same time when you said you're going to have a talk with your child tonight, with or without your AH taking part in the conversation.

I meant I'd be surprised if he did it the other night when you agreed to do it together. As regardless of what your AH says to you, he knows the reason you're separating is his drinking and his inability to be proper father and husband (but he doesn't want to know it). Also, he knows what does it take to change that but he is unable (for one reason or the other) to do that. It is much easier for him to run away and drink some more (escape some more) than to stand up and take responsibility. As if he was a person who could do as he promises and take the responsibility instead of run away from it, then there almost wouldn't be any problems.
You're separating for the good reason, because he is anable to do the right thing. That is not going to change only because you're separating now. That will not change until he himself gets to the point when he is ready to do whatever it takes. Any your AH doens't seem to be there yet IMO.
Take care