I don't think he thinks you're stupid. I don't think he thinks about you at all in those terms (smart/stupid), in my experience, I was just an other obstacle my AH needed to overcome to continue drinking.
If he was to say yes, I was drinking, than he'd also have to say he knows he shouldn't and he'll stop (Likely to happen?) or he'd have to say it's not problem. Either way the disscusion follows, the disscusion he's not ready to have, as he's not ready to deal with his problem.
So, you know he was drinking. If you wish yourself well that has to be enough. Otherwise you are just spending a precious time of your life looking for him to validate your thinking. I spend too many years of my life doing that, and IMO that's straight path to hell.
So what happens if he says yes, I've been drinking. What is different than? You know that allready. For me the way to get off that ride was to accept it wasn't personal, it wasn't about me at all, or what he thinks of me. it's only about him and his desease, and by doing what you're doing now I was just making myself a hostage of his desease.
Quitting that role is I believe the hardest thing I ever did. For me it came from utter desperation, I finally realized if I continue to do it I will lose my mind.
The more I distanced myself from that line of thinking, the more I was giving up on my expectations of him and the more I was able to see him for who has really become: someone quite close to a young child, who doesn't think about how his actions are affecting others, who only thinks how he can get what he wants: drinking, drinking, drinking....
I don't know if this helps, I really hope it does.
Hugs