Ex husband going on holiday with new family

[SmileWithStyle]

Hi All,
I'd really appreciate some support or advice here as I feel in an awkward position. My ex husband and I divorced in 2023 and we have two sons who are now 7 and 10. He has since re-married and had another child with his new wife.
We have shared custody of the boys it works around 40%-60% split, with me having them a little more and usually sorting out all of the admin that comes with having kids.
So the problem started when my ex husband went on holiday abroad with his new wife and their daughter, but the boys were not invited. His mum helped with childcare, but my oldest was really upset and said "we're being dumped at Grans while they go on holiday" which I'm gutted about. My youngest is a bit more laid-back and was upset, but not to the same extent.
My oldest son has been having tantrums at his dad's and not behaving well. He's been great with me, very few issues and we have a really close relationship. His dad asked me to speak to him about the tantrums and bad behaviour. When we had a chat my oldest opened up about not feeling important to his dad, that they don't spend any time together, that the new daughter is the favourite etc. Firstly, I'm not sure how to feed that back to his dad. I feel it's not my place to be getting involved, but on the other hand, I want to advocate for my son and how this is making him feel.
Then there was another incident yesterday. I took the boys for haircuts cuts and they wanted to show their dad, so the boys did a video call and he was away in Ireland with his new wife and child. The boys didn't even know he was going to Ireland. After the video call they were both pretty upset and frustrated that their dad was away in Ireland and they hadn't been invited again.
I've tried reassuring them that they are loved and they know that, but I think my ex husband is really damaging his relationship with the boys, especially the oldest as they're being excluded from trips and holidays.
How can I approach this? It's such an awkward one as I don't really want to be the person telling him how his actions are impacting the boys. Our relationship is pretty fragile, there had been DV and lots of controlling behaviour so I don't think having that conversation will go down well.

Advocate for your children, tell him they’re upset.

Your ex’s relationship with his kids is his to sort out so I would just say to him that behaviour this house is only happening at his house and he needs to be the one to get to the route cause of it. It’s not your responsibility to do the tough parenting bits for him, your responsibility is to support your kids through it.

They're right. He's prioritising his new family. Don't minimise their feelings, let them know you will always be here for them and in a few years when they get to choose they'll probably stop going tonsee him. More fool him.

the dad asked YOU to speak to him? You should have said no, speak to your son yourself. I think you need to be fairly blunt with him and say it’s unacceptable to treat his other two kids like this. You are not responsible for their dad’s bad behaviour and should even be in the position to need to share anything. It’s time he steps up

I’m completely staggered by the posters on here continuously ignoring the fact that the father in question is a violent man. Why? Why promote or do anything to improve the father child relationship- which is unlikely to improve anyway by virtue of anything that the mother can do.

Isn’t it best to leave the man to fail and hopefully disappear to the extent that he has no influence on these children?

No, they're not from Ireland, it was just a trip. It was a school holiday weekend too, Friday and Monday off. The boys were with their gran on Friday during the day as I was working. I picked them up on Friday after I'd finished work. It was only on the Saturday when the boys wanted to do a video call to show him their new hair cuts that he said he was in Ireland.

Was it his weekend to have the boys?