Thanks so much everyone. Knowing we're not alone makes such a difference.
We've just talked. I've been very honest about what I will and won't deal with in this situation, and I know it's true that he isn't my responsibility. All I can do is make sure my own drinking is not giving him the excuse to continue bingeing. Fortunately, he's not in denial about the problem, but I understand that it may take some time for him to make healthy changes - if at all. One day at a time for us all, I guess.