Hi Johnny Welcome to the thread, sorry you have to be here. I've watched my friend's two dc (a bit younger than yours) go through exactly what you describe. Her ex met another woman with two similar aged dc. He made his dc fit in with her and their needs, to the point where his dd was having panic attacks and seeing a counsellor.
He would post photos of himself, his gf and her dc on FB. Photos of them at events his own dc had asked to attend, or would have liked to have gone to. His response to my friend when she challenged him? He blocked her. He has been breathtakingly cruel. As far as I know my friend has taken the route of sympathising with her dc, trying to negotiate with him ways to stop them feeling so excluded, and hoping things got better.
Things have improved as his relationship has become more established. Also, the dc are older and a little more able to voice their opinions to him. I think she did stop them seeing him a couple of times when things were really bad. He didn't make too much of a fuss as it suited him anyway.
I'm not sure what I'd do in your situation. I would certainly explain in an age appropriate way that your ex was being unfair. I wouldn't try and excuse him or rewrite the situation. He's the one doing the damage, and you can't stop that. If you stop them from seeing him that in itself has fallout. You want them to have a good relationship with their dad, but you can only facilitate contact, nothing else.
You can't prevent them from seeing that their dad is being unkind to them. But you can be honest, just as you would if you were talking about somebody else's behaviour. I think it's important that the dc in our situations see their other parent being judged by the same standards that apply to all of us. These twats think the rules don't apply to them.
Hi Nats That's a pain about your ex going AWOL ! I know it means you don't have the phone calls etc but you can't get things resolved. As for GMB. Will it be Piers M do you know? Maybe one of the Liberty people could go on with you? It would be fantastic publicity, but I can see why you have doubts.