I disagree that they are necessarily "controlling it" (or trying to control it) just to pull the wool over the eyes of the partner. I lived all alone and had my rules and conventions. The only one I was trying to prove anything to was myself. I didn't WANT to be an alcoholic, dammit. And I was sure if I just kept trying hard enough I would get a handle on it.
Well, we all know what handled whom. Anyway, the point is that even if there is an element of trying to conceal the amount they are drinking (not uncommon and I did that when I lived with someone) it is at least equally the case that we really, REALLY don't want to be alcoholics. Not enough to quit, maybe, not just yet, but enough to try for a very long time not to be.