What should I do? I hate his family

My husband and I get along very well until he starts having more contact with with family. Everytime he is with them or on the phone he starts changing his attitude and treating me bad. I'm not sure if it's to make his family think he's the man of the house, but I don't like it. I don't like his family nor him when he's around them. He becomes a whole different person. What should I do? I've spoken with him about it but nothing changes. I really hate his family. Bunch of problematic/drunks/pathological lying people.