Narcissist and heavy drinker girlfriend

Anyone have experience to help me understand this relationship.

My Ex was a psychopath with a long history of abusing wives and his children.

He is now in another relationship. I do understand after many hours reading this board and in therpay that he can never change.

All I do know is that he has been with GF for nearly two years. When I was with him he was a very heavy drinker as his ex wives will also confirm. In fact don't know how his liver is still functioning. He was a psychopath, cruel, abusive, sadist, liar, womaniser, brainwasher, emotional and physical abuser to woman and his children.

His GF and her friends who he now socializes with are all heavy drinkers.

Anyone have any knowledge of what a relationship would be like between an alcoholic Narc and a woman with a heavy drinking woman? BTW she now works for him and he pays her wages and she lives in his house if that helps with further info.