Rape is one of the worst things that can happen to a person.  If this was with a prior relationship and there is no substantiating evidence then the question arises whether this is a matter of her perceptions after a relationship ended (horribly in her feelings).  You may never know the reality.

The common BPD perception is that all ended relationships were bad and the worst ever.  Even the new wonderful relationship is perceived as horrible once the early adoration phase is past.

The patterns we see here can vary.  Often commented upon are the abandonment issues and subsequent retaliation overreactions.  Sometimes the person with BPD traits (pwBPD) finds the relationship too difficult and abandons the other before the other can abandon them.  What we also see here are the cases where the pwBPD drives the other away, forcing the other away.

Human traits vary from person to person.  Each one of us is different from another person.  That's what makes us different from robots off an assembly line.  That's all good and positive.  But still there are norms which make relationships not only possible but functional and enjoyable.  Drift - or leap - too far away from functional normalcy and those same traits become dysfunctional, unhealthy, even somewhat dangerous to others.

Since oftentimes there is little lasting positive impact on the pwBPD's perceptions and life choices, we have to decide what Boundaries and decisions we ourselves have to make in response to the poor and/or negative behavior.  And if the other resists or is unresponsive to therapy, too often it comes down to the stark decision to protect ourselves and the children.

Just tell them she isn't able to come and then just go. No more needs to be said. They may wonder why she isn't coming but as soon as they get to Disney, they are going to have the time of their lives. You are the one with the history of an adult romantic attachment to her. They don't have this attachment. They are more attached to you as their father. She may be fun for them, they may like her and want her to come along- at about the same maturity as they'd want Mickey Mouse to come with them too- and they will see Mickey. You don't have to worry about them in this sense.

They can't understand your perspective. Maybe I'd have felt like they would if I only saw the "good" side of my mother like they've seen the short term good side of your ex. However, I have been on family trips where BPD mother did not manage well. On a family trip, 24/7 with kids all hopped up on excitement, snacks, Disney excitement, they won't be little angels. I've done Disney with kids and sometimes they have melt downs from the stimulation, being tired, while still also having the best time. This may not sit well with BPD ex. What you are doing is protecting their Disney trip from seeing the side of her that you see now.

In addition, there won't be the kind of dynamic and drama with your ex that takes attention away from the kids. My best memories of Dad were when we were alone with him. When BPD mother was there too- she needed a lot of attention and Dad's attention was on her. Sometimes there was drama during the trip. Dad was also was  more relaxed, less tense when he was with us and she wasn't along.

This is a chance to have an amazing time with your kids and an unforgettable good memory ( we have both good and not good memories of family trips) for all of you. That she isn't coming could be a big plus overall. You don't have to worry about her and can do only kid stuff and so do that - all of it- get the ears, the T shirts ( you can order from Amazon ahead and bring them much less costly than at the park, take lots of pictures. Go on all the rides, see the shows- do all the kid stuff and give them your undivided attention. You all will have the best time.

The four of us were due a Disney trip in a few weeks. She won’t be coming now. I said what do I tell the kids? They don’t understand. “Tell them I’m a c**t”

That was the final straw for me

I agree- it is vile. As an adult, I could rationalize that she was mentally ill, but that doesn't change how it feels to hear that. Just consider you spared your children from hearing her say things like this to you, and possibly to them.

This is projection and from victim perspective. If she's feeling hurt at the moment, she perceives you as the cause of it. She's saying vile things- which is projecting her feelings at you. That doesn't make it OK to do that. It's a dysfunctional way of  managing her own uncomfortable feelings.

Will your ex realize her wrongdoing one day? It's not possible to really know that. Projection, dissociation protects them from shame, and it's possible she isn't capable of realizing that. Sometimes their own sense of self is so fragile, these defenses won't allow it.

You are in the thick of it now and while it's understandable that you are thinking about her actions and words, really for her, it is sad that this dysfunction affects her relationships- but you didn't cause her to have BPD and you can't fix this for her, even though you had wished better for her. But you can preserve your emotional safety and that for your children. Whatever she thinks or says of you- one can not change another person's thinking. It doesn't define you.

Maybe….its just a vile way to do it. Thing is I know how much she has been struggling with the police investigation. So I know it’s not truthful what she said. I hope she can at some point actually realise what she said was wrong

From my own experience, it's not only at an end of a relationship, as one doesn't "break up" with or divorce a BPD parent. Some may go no contact but it's not the same. I didn't go NC with my BPD mother. It's about the pwBPD's disordered thinking and feelings in the moment and that to them, feelings feel like facts.

It's splitting, black and white thinking,  projection and victim mentality. The end of the relationship can't be about her, she can't be accountable. So it has to be about you, you are the horrible one.

Looking at my situation from childhood on -As kids, we were mostly well behaving,  but if BPD mother was upset with us, it was as if we were the worst kids ever. Other times, if she was pleased, she'd compliment me. Hard to believe that but in a way, I think both were true in the moment- it was her emotions that changed in the moment. For someone with BPD- feelings feel like facts.

You were all of it according to her feelings- the best partner ever when she felt it and now, you are the worst person on earth according to her feelings in the moment. But just because someone isn't perfectly wonderful all the time (nobody is) does not mean they are a bad person. Just because your ex says something doesn't make it true.

Imagine she's calling you a pink elephant at the moment. Would you consider her words to be true about you? I don't think so. Neither can her saying it turn you into one.

I’m not sure if it’s common. But when someone with BDP perceives it as the end. Is it normal they use that opportunity to say some really really horrible stuff? She has an open investigation against someone who raped her and exploited so badly and I’ve been supporting her with these investigations. The person is obviously no more at all

Last night she said I am the worst person she has ever met….i said wait about this person. She did this laugh and smirk (the laugh sounds so sinister) and wouldn’t add anything. However, later double downed!

Do she really think this? Cus it’s not the break up that’s hurting it’s that comment it’s broke my heart

Somehow a conversation (one of hundreds the past several years) trying to help my PWBPD issue turned into a chance to comment on my failures.   I made the mistake of speaking honestly about how I felt and my SO took it as me blaming them for everything wrong in my life and then went on to attack me for the failures and talking about how awful I was for even including them in any comment about them. 

I realized too late, as I sometimes do that I made the fatal mistake of being open and honest, something my BWBPD can do anytime they want, but I can only do if it is about something or someone they don’t care about or share identical feelings about.   

So I’m painted black and sitting here thinking about all the hours I’ve bent over backward doing things for them that are apparently my duties as a partner but realizing I’m allowed to have no expectations.   

I’m supposed to be what they need when they need it. My existence is secondary. 

And feeling incredibly alone, that hurts.   

It's not vile. It's realizing this relationship is not an emotionally safe situation for you and your children.

Naturally, I speak from the child's perspective. A pwBPD can be nice during visits but the long term relationship is different. Moving forward with this relationship would mean your kids are exposed to the whole picture, the dysfunction, in their own home 24/7, even if there may be some "nice time" moments.

Likely when this former GF is visiting, you are there too. She isn't acting as a step mother on a day to day basis with your children, sometimes when you would be away.

Understandable that you don't want to be hurtful to your former partner, however, its not about choosing to be hurtful. It's about choosing the emotional safety of your own family- self and children. It's about not compromising you and your children's emotional well being to spare your ex GF's feelings.