It may very well be BPD.
She has a way of lying to people.
In their minds when they lie, are they telling the "truth" the way they see it?

I believe she has painted me as a dangerous individual. That's far from the truth. But that would explain his need to protect her.

I kind of feel foolish. I mean, here she is, in the arms of another man, and here I am missing her.
She just met him, their first date was 2 days ago. He's been at her place since. The most disturbing factor is her kids are there and see mommy and the new guy.
I'm a single father. I certainly wouldn't bring home someone I just met.