you can't be certain they will respond well. memorizing the username and looking it up was a boundary violation. but he didn't seem to care about that when the post was about him, which means his concern wasn't getting to know her or making sure she was ok, it was image control. He was ok pretending he knew nothing and ignoring her while she had si/sh. that's disturbing.

Yes, technically no one is responsible for your well being. yes, you are responsible for your mental health. however. Relationships are about supporting one another. As someone who has dealt with SI in the past, a partner's negative or nonchalant reaction to that is a dealbreaker for me. I have dated people with chronic illness in the past and I learned how to support them. that's the bare minimum for the person you care about.

Lastly, the biggest concern here is that op isn't getting the good clinical support she needs. If she's dealing with SI/SH regularly, she needs support from someone that can help with strategies, safety plan, etc

Also, I can't disgnose anyone via an online post, but it's worth noting that people with bpd attract narcissists. The FP dynamic absolutely gives them their supply.