Hi Nina ~ I"m sorry you feel badly about this and had a little blip over it. But has he EVER given you reason to doubt him? Has he ever cheated on you? Have you ever found questionable numbers on his phone? Have women ever called him & talked with him? Have you ever found numbers in his pocket or anything? Do you have ANY reason at all to doubt him? If the answer is no, then why not let him go?
I realize you dont' like him getting drunk, and I wouldn't either. Alcohol is dangerous -- I should know, as I'm a recovering alcoholic. If he keeps drinking like this, he could cross that invisible line into alcoholism. But the question is TRUST. Why don't you trust him?
Does this have to do with previous relationships where someone cheated on you? Are you expecting HIM to cheat on you too like previous BF's did? If he hasn't given you any reason to doubt him, don't judge him before the crime has been committed. Leave the sentencing until afterwards. God bless & take care. Hugs, Lee