My initial reaction was for you to write her an email with the largest font available:
HAHAHAHAHAHAHAHA!!!!
OK, not a good plan.
But what you do have is UNallocated support (which is very, very good for you and sucks for her - you get to deduct it on your tax return, while it is all income for her, and therefore, she must pay taxes on it).
Another possible response to her:
"I fulfill the requirements of our agreement. Please highlight the sections of the agreement pages that you find that I have to reimburse you for, if you think there may have been an oversight. If there is an old bill or something else that you feel needs to be 'caught up' with, send me a copy of such, as well."
Be a broken record - don't buy into or respond to her last paragraph of delusional thinking.
I learned an incredible phrase here that I have used until my ex finally realized what my boundaries were and started to respect them: "That (whatever crazy demand they have) doesn't work for me."
If I am in a generous mood, I might even provide a counter-proposal. Otherwise, he is sh*t out of luck and will have to take it up with someone who cares.
Then you occasionally buy your son a team sweatshirt (or similar example).
I don't expect a thing from him for the kids outside of the agreement. This summer, my S got a job working at Boy Scout camp. Our agreement calls for both parents to split the costs of summer camp up to a certain cap. S was being paid, but had to buy uniforms (about $230) to wear for the job. I sent his father the expense, but was told that "clothing is part of the child support I pay you." Without another word to him or my S, I just paid the bill.
