how do you get someone to break up with there bf?

It's been going on for over 8 months and she's been peer pressured into so many different things and won't see it it's so hard for me and her other friends to watch her suffer like this. It's not abuse but it's him choosing his friends over her the other day his friend called her a dirty tramp and said he hopes she dies then she apologized to him for something she didn't say. He peer pressured her into sex when she didn't want it (actually rape they. Are both underage ) and there has been so many other instances where he's been jealous of me and her hanging around so much and he has hit me because of it.

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