Alcoholism for him Produces Inappropriate Behaviour

My husband was at a party on the weekend and he got drunk and he grabbed the hostesses breasts when they were alone in the kitchen together. It was a terrible scene and probably the end of a friendship. This s not the first time that he has done something like this but every time it happens he is drunk and then he just denies responsibility for it the next day and acts very sorry about what he did.

I would like to understand why he does this and if being drunk means he really cannot control his actions. Does he have some sort of sexual compulsive disease or something like this. He is a really sweet guy almost all of the time so this is really not in his normal character, otherwise I'd certainly not be sticking around to find out why he keeps putting me in this situation.