Great job on the internship situation! Definitely a great GAL opportunity.
I'm with Abbey, it sounds like he's drinking or won't be too long before he's on that path. An alcoholic keeping beer in his fridge is like a heroin addict keeping an unspent hypodermic needle full of junk in their arm. And his constantly being around drinkers is like passersby accidentally bumping into the needle. With that set-up, it's only a matter of time.
I wonder...is he with OW because she enables his drinking, or is he drinking because of the guilt he feels about being with OW and choosing to ruin his life and M? Hmmm...makes you wonder.