It’s kind of a popularity contest. Both parents are regarded a little badly in divorce. Subconsciously, they see that you abandoned the family and they’re hurting and the only safe people to hate-on are you, their parents.
But they love their parents and they will unify with their parents. Eventually.
If you hate your spouse…..Here’s a FACT that you can use any way you want:
The spouse who bad-mouths the other parent, LOSES.
I know, right?
You’d think the bad-mouthing lying parent would sway or “poison the kids” to their “side” but the FACT (in every single divorce I’ve been through, or observed intimately):
The bad-mouthing parent soon falls out of favor.
The kids get exhausted by the venom, they stop responding to the hostile-parent, they don’t admire the unkind behavior, they may silently defend the down-parent which creates ‘distance’, and the down-parent is still their parent and means as much to them as ever. The kids know the flaws of both parents. Very well.
The parent who bashes the other parent just fucks their own-self over.