I was on that rollercoater for a long time. I got sick of it, he begged and promised to act better, I believed him, then it got bad again. You cannot totally put all the blame on the alcohol, because you have the idea in your head if they would just quit it will all be solved. It is so hard when they can be the nicest person when they are not drinking and then do totally terrible things when they are. My ex had an affair with his brothers wife. He blames it on the alcohol. Because someone is an alcoholic, it doesnt entitle them to a "get out of jail free" card. If he is doing that right under your nose, imagine what he is doing when you are not around? You deserve better than that!! believe me when I say, you wont just be able to forget it, and now when he is really drunk you will want to follow him around and see what he is up to next. My exs infidelity was 5 years ago and it is still a sore subject. Dont do that to yourself, you deserve more!!!!