My first thought when reading the above follow up post was "YOU HAVE NEVER HAD A CONVERSATION WITH HER ABOUT HER DRINKING!?!?!?!".. but then, I remembered;
Her words mean nothing, your words mean nothing.. it's all actions. So you ask what to say, how much etc.. eh.. why bother?
Your actions show that you're accepting of her behavior.
Your son is probably twisted up inside about what he's grown up with so far, to put it bluntly.
I hope you have a talk with him, and offer him some outside help. Since has no choice but to live in this wreck.. at least present some assistance with coping with everything, and keep lines of communication open. And be prepared to answer "Why haven't you done anything to protect me from this?"... I grew up in a similar situation, and quite honestly it saddened and scared me that anyone would knowingly choose to expose me to what I was.. but I grew up in foster care, and they didn't really 'care' much anyways... but as a child, you do look up to adults for actions that show protection, courage, guidance..