Creed is right, you can control what you want to hear from people. If they start talking about xh then tell them you don't want to hear it and if they continue walk away. If they can't respect your wishes then they aren't a true friend.
My stbx MIL was the same way. She used to call me and talk about stbxh and his new gf until I told her I didn't want to hear it. I told her if she wanted to continue a relationship with me then she had to not talk about him. I don't care to know what he is doing.
