I found Codependent no More really helpful in this general area.
It does deal with difficult behaviour from others (which is up to them of course) and looks at how your own feeling and your own life needn't be impacted. It doesn't deal directly with this kind of scenario but there are many parallels to make I think.
V has also posted quite a bit about high conflict divorce. Personally, I would aim for absolute serenity and firm adhesion to fairness in all dealings WRT him. And how he behaves? Well, that's up to him....
Xx
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus