I think a friend of mine has also bpd . A few years ago he met my best friend and the were in a relationship and a year ago they broken up and he is still obsessed. He even went to her place of work after he told him to leave her alone . I'm trying to set example for him to go and seek help and I'm very open for going to therapy because I want to make my best friend feel safe and him feel better about the break up. A few month ago he told jokingly some of my friends that I was a rape victim after a flight we had and I was so mad and he was like "haha are you ashamed?" . I blocked him on everything then for months but I happened to hang out with the same group as him and he apologized and I told him we could start over as long he didn't talknto me about my best friend and we were taking it slow . He never took it slow and he was texting me 20+ messages the day and I tried to reply every other day and he was like are you ok why are you not replying. I felt so much pressure . When we hanged out one day I talked about when I was obsessed with a guy and how delusional I was and that was that pushed me to go find help. And I said that I even searched him in linkedin. And some days later my bestfriend told me that he send her a friend request there. I was so mad but my bff didn't want me to tell him anything. Also one of the reason I still talked to him is because he told me that he would go to a therapist and I wanted to make sure he would . Still to this day he hasnt seek help. But he talks to me like I'm his therapist and I feel so tired because I have my own shit going on. The day before yesterday he asked me about my bestfriend and I told him that I have asked him to not talk about this and I told him how much pressured I feel . And I haven't talk to him since then and he tells me that " I always want to be right and that he feels wronged". But honestly I only set one boundary and he hasn't respected it  and I'm so tired. I really don't want to abandon him but I don't have the energy anymore . If he started therapy maybe I would give him another change .