Fuck I'm angry for you.
What happens if you reply:
For fucks sake, dickhead, these are your CHILDREN. They need money to have a good life. You are not my boss. I am not an employee required to submit my expenses.
Do you know ANYONE else who has this set up???? I don't. Not one single person. This is not normal and it is not acceptable. It is also just 1 of the reasons I am no longer in a relationship with you.
You are their father and I see this as neglect and abuse withholding what they need. You will look absolutely tragic to everyone when it is revealed in court. Just transfer me the money and get over yourself.