I agree that it was crappy of her to break the explicit agreement that both of you had put in place about introducing BFs/GFs. You two had talked it out and agreed to ground rules which she then ignored at the first opportunity. That said, it can't really be a boundary because you have no means of enforcing it. You can't control whom she introduces the kids to or what she does with the kids (obviously within legal limits, if there is abuse or a dangerous situation that is another matter) during her time. If you can't control it, you have to let it go. Letting it affect you emotionally and mentally is giving it undue power.
It seems like you feel that you have been fair to her and held up your end of the bargain. Great! You should. But you should do that because it is the right thing to do. If she fails to live up to her end of the bargain it is on her. Don't take on what isn't yours. Meeting with her in person to explain how you see things sounds like perfectly fair and reasonable step. Just don't expect her to change. Zero expectations. Similarly my W seemingly can't acknowledge that she walked out on our MR. I told her that's how I saw it, but it certainly didn't convince her because it isn't the reality she is living in. That's okay because I went in with zero expectations and full awareness that I can't change her, only she can do that. Same with your ex. Express how you feel about the situation so that she knows and can change her behavior if she chooses. But don't expect that.
W 34 Me 42 Married 7 years together 8 0 kids 1 beloved dog BD 4/6/2018 I moved out 4/7/2018 I moved back in alone 8/05/2018 I file 3/06/2019 D official 5/7/2019
