So my boyfriend of a few years has a crazy mother and family and general...and now they hate me!

In the beginning we all got along (my family and his). His sister was always causing controversy in the house so she was the focus of conversation until she moved out and they liked her again. Apparently they always have to hate someone including one of their kids bfs/gfs and/or their families. I am a very independent and strong minded person and did not take her advice on something very simple (to turn around in a snow storm on the way to visit her son in ct after i had already made it through the worst of the storm) i wanted to keep going bc i didn't think it was that bad. So, she didn't talk to me for a month. Then at xmas, i apparently thanked his grandma for making cookies and it was her. then she had a backround check on me and my family and found stupid reasons to hate me ( i was hurt by someone when i was younger). So now, my bf has 2 lives and i don't exist when he goes over there ( i haven't been there or spoken to them in over a year), and he never tells me anything about them. His family said they have disowned him and other really hurtful things..but he still somewhat wants them in his life even though he says he wants to move far away in the next year. I am the type of person where i want to directly talk to her and ask in a nice way what the heck her problem is...but he won't let me talk to them bc he says it'll make things a lot worse for him... what do you think?