is there anything i can do about my best friend?

[jes!]

basically... my best friend is in an abusive relationship. she just recently told me that he hurts her when they fight and that she is afraid of him when they fight. So i told her she should end it now before it gets worse. but she loves him and wont do that... anyways... she broke her phone and started txting me from his phone, which i thought for a second HE was txting me so i said ''fuck your boyfriend'' and he needs help and blah blah blah. Anyways, i recently saw her again and she said He is mad at me because i said that. but honestly i dont care anymore, he WAS cool when he didnt hurt my best friend. so now i basically hate him. but i am really close to her sisters and they always have family get togethers and sometimes he comes but me and some of my best friends siblings dont talk to him bcuz of what he did to her. what can we do? he says he doesnt need help and wont get it. and ya ya apparently its ''none of my buisness'' but ive known this girl for 6 years and she is like a sister to me and i really dont want this guy to do anything bad because i WILL result to kicking his a**....