To have expected this?

[Lamee]

So my ex had the doctors on the days he was supposed to have the kids and he said he couldn’t have them so I had them instead. However, I said to him if I have them on your days can you have them on Friday and he just wouldn’t answer me, finally got hold of him yesterday and he said he said he would have to speak to his GF first? I mean what on earth has it got to do with her?

You procreated with a sleazebag who puts a woman (or any other human he may have a plan to make plans with) above his children. It won't get any better. That's who he is.

Just make the kids available on the days he should have them and then keep them with you the rest of the time.

Your kids have got you. They don't need anybody else, if he doesn't want them don't push it.

Don't make excuses for him to the kids, don't become his enabler, his protector.

Let him be the bad guy, don't bad mouth him, but don't make excuses for him.