My Mother (rant/what to do)

I'm so sick of it. My brother loves my husband a lot, he has been around a good portion of his life ( my brother is 12, my husband has been around since he was 7). My husband is the brother my brother never had. All three of her past boyfriend talks shit about him and I. Because we have a three strikes you are out policy. Now she's on her 3rd boyfriend in five years, and last night my brother came to see us and started talking about how it makes him (my brother) feel when my Moms boyfriend calls him a disrespectful jackass and what not (we aren't talking to him or my Mother for different reasons.) My brother is here every evening once my husband gets home. If he needs something, my husband and I or my Dad & step Mom get it for him. But I'm sick of it. (Her attitude and talking shit) What would you do?