Antlers: I like Fig's suggestion and totally agree. We KNOW that your ex is not going to do the right thing. I can relate (as many others here can). My ex did whatever was "all about him". I could not count on him for anything and that included what was best for the kids. So I always did and learned to keep "zero expectations" of him. However - having custody helped.
Get the school onside with you. Let them see that you are there and you are involved. Son needs to see this as well. Keep a record of what goes down. You might need that info in the future if you do have to go back to court regarding where son will live.
Just leave it be with ex now. You tried to get her support. She is not willing. Just don't let son fall through the cracks of the school system as a result of his indulged behaviour.
