Long story short I have this friend who has BPD aka Borderline Personality Disorder. She's had episodes where she has lashed out, tried to commit suicide, and has engaged in self harm. She just got out of an abusive relationship. She is currently getting close to a guy who's ex gf I was friends with. The ex gf left this guy because he was abusive: physically and verbally and emotionally, stalked her and threatened her and also would threaten to kill himself if she ever left him. Should I do anything about this? If he does something to her and she ends up hurting herself I'll feel some intense guilt. but I know it's also not my place to say anything, but holding this knowledge is troublesome.