DBBD, new girlfriend, new baby. AITA?

I have a DBBD who has pretty much abandoned our kids (6&8) since I broke up with him in 2020. The last 12 months he has had a girlfriend who already decided she didn’t like me before me knowing about her. DBBD has seen our kids about 3 times since they’ve been together and the few conversations we have about the kids she always involves herself/oversteps the boundaries and makes it about her. I once asked for my kids clothes to be returned and I was the toxic drama one since my kids have “more clothes”. Besides the 3 times they’ve spent a few hrs with the kids, they’ve had no contact whatsoever and they literally live around the corner. Now that DBBD and new gf have had a baby of their own, she now feels entitled to have and see my kids but asked in a complete disrespectful way and wouldn’t even try to understand where I was coming from by telling her they can’t pick and choose when my kids matter and they’ve deserved the respect since day one - not to be ignored and made to feel like they don’t matter UNTIL they had a child of their own. Now after them ignoring and disregarding

my innocent kids for months on end, I’m the bad one for not sending my kids with them to meet their new sibling they know nothing about since they never thought to let the kids know she was born. AITA? What do I do in this situation?