Geez. Im so sorry. Your mother gets some payback from being there, thats her husband, but i think she needs you there to dump her own unpleasant feelings into. If she had decent boundaries...

A "solution" would be to say, hey ma, lets you and me do stg together sometime, and just get the hell out of there. If she chooses to have those kind of people in her life, great. You dont, and i dont blame you. I wish you peace. You deserve it.