Obviously I don't know much about your situation, i.e. how long you've dated, how long he's been an active alcoholic. Here's what I think based on mine:
Advanced alcoholism can cause the A to isolate and break off relationships, parents, siblings, wives, etc. This happens because they no longer want the the pressure of measuring up to the role of son, father, husband. They want to get rid of those expectations and take up with new friends where nothing is expected of them. So that may drive the A to get into new relationships -- I don't have to be dad and breadwinner, I can just drink drink drink with my new girlfriend who happens to be in the adult entertainment business.
At the same time, I think my AXH reaches out in moments of clarity, although it doesn't stop him from doing whatever he was going to do anyway. So... he may call, call, call - leave me an urgent message to return the call, then not answer when I do. I no longer return his calls, but it strikes me that he's looking for a life-line when he reaches out, then he changes his mind and reverts back to his alcoholic altar-ego.
My XAH repeatedly quacks about being friends. When he first started saying that, I would explain how after 21 years of marriage, I can't just become a buddy, while he dates other women. How could you meet for coffee and discuss his new gf, after years of having a long-term intimate relationship?? My ah never got that, and I just chalk it up to his scrambled brain. He seems to genuinely believe that being friends is reasonable. I also think he's motivated by guilt. If he could tell everyone we just met for lunch, then he's not so bad -- right? He can rationalize that what he did to the family wasn't a big deal since we can all be civil and make nice.
My 2 cents worth...