What does seem to be a common denominator, depressingly common, and almost always overlooked by all - the man in these AIBU situations. However tricky the scenario, he seems to float above and separate to it all, somehow opinion-less, blameless - verging on invisible with seemingly no input to decisions
I can see what you're saying, I've seen a few exchanges which suggest that's the case.
In our case, DH has always stepped up to the plate for DSC and is a good father. The problem lies with how he deals with any conflict with his ex - in short he doesn't.
He falls short hugely in this regard.
I have no contact whatsoever with her now because of the way I have been treat so everything goes through him, as it should.
Unfortunately for me this means that any issues I have are never acknowledged because he is a peacekeeper to everybody's detriment.
It's like the covid tests thing. Last year he and I agreed between us that DSC needed to be tested before going between households if they ever had symptoms.
I stressed that he must relay that to his ex, as we would be keeping to our side of things and testing them if they came down with symptoms whilst with us.
Suffice to say ex sent them here, more than once, with covid symptoms having had no tests. We then tested them but that's besides the point, if they had been positive they would be kept here with us regardless and everybody else would've been exposed including my CEV elderly relative who I was in a support bubble with for the purpose of providing care.
I was extremely upset about it and DH got both barrels, he didn't relay any of that back to her though. He would sooner I get upset and he gets it in the ear than take any sort of stand against anything she says or does, because she'll whip out the "you're not seeing them" card.
It's very spineless.
So whilst I will always maintain that she's a very toxic person, I fully acknowledge I have a DH problem aswell.