I woke up this morning and realized that I should have presented things differently to my ex. I should have "offered him the opportunity" to pay for half our daughter's trip to London. I thought that was what I was doing, but he didn't read it that way. Perhaps I should have suggested it as a graduation present. I could have asked for his input on whether she should go, but that seemed disingenuous since I had already decided she was going no matter what and that I would figure out a way to pay for it.
The bottom line is that I forget sometimes that I'm not dealing with a grown up, I'm dealing with a petulant, spoiled child. Am I sick of it? You bet. Do I resent it? Of course. Do I think he needs to grow up? Absolutely. But he is who he is and I need to remember that when dealing with him. I used to be better at it, knew how to frame things in a way that would manipulate him, but lately I am tired and over worked and it seems like a lot of effort.
It's an expensive lesson, though, in order to be reminded that I can't talk to him adult to adult. Next time, someone please remind me before I approach him about anything! :)