A girl in my boyfriend's life is bothering me.. [I Need Advice]

My bf's cousin has a girlfriend who has been around the family for years. She's not well liked by a good majority of my bf's family. She has a major drinking problem and she has had issues with violence. She lost her last job due to beating up her coworker. When she drinks she tends to get rude & make dumb decisions including cheating on her bf 3 times.

Now my bf's cousin is wonderful. She's the only problem. Now while she's nice to me, she's constantly trying to get my boyfriend to hang out at her place with his cousin. Almost every night. Almost always involves alcohol. My bf always trys to go because the girl will be mad if he doesn't and she'll continue to bug him. My boyfriend is a sweetheart and won't say no to her but I feel she's such a bad influence and I dont want him out late with her.


What am I supposed to do??