Problems with my baby’s father

I’m probably going to get scolded for this post but idc. I’m having issues wit my ex gf . His gf is not a good person, she’s a home wrecker and literally threatens him every times he comes to see his child. Anyyy way, my ex and have been good Now all of the sudden he blocked me and I can’t get a hold of him about our daughter , I know it’s his gf threating him bc she does this every time and pays his phone bill . He told me that he hates how he has to sneak around her back to see her child which makessss noooo since bc when he sees his daughter it’s at his moms house not even with me . I’m trying not to be petty but I’m really about to tell her off bc she’s reallly pissing me off. With being so possessive. Should I just let there relationship die out or should I say something to her