My friend and her boyfriend broke up. He cheated on her. But before the break up I saw him with another girl not knowing if it was real 或者 not i kept my mouth shut now i feel like this is all my fault what should i do

as 你 say he cheated on her so thats his fault not yours

dont say that thats his fault not yours but
你 could tell your bff about what happend

just be there for your friend she's prolly going through alot already, but if she asks about it 或者 你 feel that telling her is the best way to help her than tell her the truth, it's not your fault, what would have happened different if 你 had told her befor, he was still cheating, and she is still hurting, just focus on what 你 can do for her now

since they've already broken up, u dont have to worry. maybe if they werent yet, then u cld worry. but for the future, if u see something like that and she's still together with the dude, tell her.

honey,its not your falt.:)