A couple of psychiatrists told me somehting stark but helpful years back during an extremely traumatic tie. They said that children will be harder on, and 'take it out on' the safe parent, or the parent who to them feels safest. ("Oh, great," I thought at the time, "more s*** to look forward to.") It turned out quite true, but it did help to know in advance it'd be happening.
When your ex trashtalked you to his own offspring, he was absolutely placing a red flag on his own head indicating that he is not safe. I'm sorry that happened to your child and to you
@Lane. I know about how it goes first-hand, unfortunately.
You are a kind and strong person and a good parent. (h) if they help