My boyfriend and his ex girlfriend keep arguing, should I leave?

She been texting him and calling him. he rarely say something about it. he said she was nothing but a sex to him. This has been going on contiuously. He was talking about filing a harassment report against her. I talked to him about it but I think he did it because I was there. It seem fake because he's not taking the report serious. I seen the messages. His ex girlfrend said "you talk To a million girls but you gonna call yourself disrespecting me" my boyfriend replied " don't worry about what I'm doing. " he told me he just sex with her at the back of his car and that's it. He even said he wasn't gonna text her anymore. He texted her and when she called he answered saying "hello". I'm like what the ? So he have me to call her and I called restricted. Out of this whole ordeal he only told me twice she was bothering him. He stay on Facebook more than ever. him and his ex argue constantly. that harassment was filed in August nothing has changed. So I'm thinking he did this to throw me off. we even got a copy of the order but for some reason only he can see it. this has been going on constantly. He even told me she change her number constantly to harass him. I later found out she change her phone number all the time just to change it. He be telling her he don't want her but never do anything to get rid of her. he even called her while they was arguing. should I leave? Even on twiiter after 2 months not being on, he tweeted about her because she always see his page. He hasn't been on since. I live with him and he say she nothing but a sex to him but why can't go further to get rid of her? He even had a lock code
My boyfriend and his ex girlfriend keep arguing, should I leave?
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