you really have nothing to lose by doing or saying anything in the process of ending a relationship... .
Except that there is a human being on the other end who will be very hurt... .in the case of BPD, where rejection sensitivity is very high, hurt more than others.
I left a relationship of someone I loved. I think it is not so much a matter of accurately disclosing your reasons for leaving, but more a matter of releasing with grace and dignity.
This author of this article (
https://bpdfamily.com/bpdresources/nk_a125.htm ) suggests going through a step-wise series of being disinterested and increasingly distant. When the partner has the typical reaction to pull you back in, you say "its nothing, there is nobody else", but stay the course. After a few weeks of this, the partner will be start to drift from a rejection reflex to a defensive reflex (I deserve better). You can then do a trial separation or say you need some space or say "you're wonderful but I'm not feeling it". If he over-pursues at any point, tell him he is pushing you away and ask for space. The idea is to invest a few weeks (no more) and back off in increasing stages of carelessness (but not disrespect or maliciousness). It won't hurt as much.
In my own thinking, the way people get damaged in breakups are 1) if the are betrayed (dumped for someone else), 2) ghosted (this is horrific), or 3) the relationship is terminated for personal defect (BPD, has a child, doesn't make enough money, too short, didn't go to college, etc.).
