My xBPDgf dumped me for a married guy she'd been seeing (and getting high with) off and on for a few weeks, while we were supposedly trying to repair the damage of their affair. The next day she insisted that she loved me and couldn't picture me not being in her life, just not "romantically," because she had to be with someone else "for now." But we were still soulmates and she could see us getting back together "one day." She also said she had a feeling she would wake up sooner rather than later, possibly sober, and realize she had made a "horrible" mistake, because she had feelings that would not go away. I am honestly not sure what her feelings were, because in most cases it was a sense of guilt for hurting me rather than missing me or trying to make amends (or so she claimed).
Even if she felt these things at the time, expressing them is totally unfair. Most people don't wish to add confusion and ambiguity to an already difficult situation.
I had to read that twice to make sure that I had read it correctly. I am so sorry that you had to go through that situation in your life... It must have been very painful. What struck me with my situation, I see here in yours so clearly, is that with pwBPD they act as though they are the only person that matters, we are just an adornment or better yet an accessory. The level of self-centeredness and to me, outright cruelty is just mind blowing. I identify with your situation. In my case my pwBPD did similar actions yet expressed no guilt at all. It was very damaging to my psyche. Hope you are doing OK.