Honestly, my gut is telling me no matter what the progression is here, it will end very badly and my goal is to protect me and the kids from damaging drama.
There is no way to completely protect yourself and especially #1 priority the kids. That is why so many, after trying so many options and strategies, finally conclude that it is the dysfunctional relationship at the core of everything. You can't fix the other. You can't consistently reason with the other's inconsistent moods, feeling and perceptions.
I really tried but failed to hold the marriage together. That's why I accepted that divorce was the only alternative left for me. (Even before we separated, when our child was a preschooler, my spouse was threatening to zero my parenting by disappearing with our toddler.) Not only was I being disparaged and disrespected, I was no longer seen as having any authority. So I turned to family court which, strangely enough is The Authority in today's society. It's not optimal and is often far too passive in the face of obvious obstruction and sabotage, but it does limit the damage in many ways.
I was able to establish my own home, a calm and stable one versus the endless conflict and discord of a joint home environment, where my child could experience the contrast between my home and the ex's home, the contrast of my norms versus her, the contrast of normalcy versus whatever happened at the ex's home. Yes, mine wasn't a perfect example, but it was far better than before. And it set a limit to the chaos and mayhem. All for our child to learn from and guide his future decisions.