My ex was a quiet drinker. He was nice when he drank, open, loving, friendly and just a happy guy. He rarely got drunk around me, but would do it during the week at home, at night.
This is when he was alone and had the time to think. Thinking for him meant feeling his shame and low self worth and to reduce stress. When he stopped drinking, he still was left with all his feelings so to reduce stress, he took up "women hunting" (I wish he never stopped drinking actually)
He was never an ahole when he drank, but more of an ahole when he wasn't self medicating.
And when I say ahole, I mean, lying, gaslighting, emotionally mean, verbally mean.
He's been sober 2 yrs now and in step group a few months and we are no longer together, but email here and there and he tries to be nice, but still has a tone of pain and self hatred.