How to get bff to break up with her bf

So me and my bff have been bffs since 5th grade day 1. We are now in 11th and she got this boyfriend that treats her so wrong. All he wants is to have sex with her. Well they already have and everything and I hate that for her because she’s so innocent. She goes to his house, she walks with him in the hall, she forgets about me. I don’t want them together not because she has a bf just because he treats her bad. He said if she got pregnant, he would kick her stomach until the baby died. And one time, I told him he needed to chill out and he said ,” SHUT THE FUCK UP “ like wtf. Someone help