How can you agree in a divorce about unexpected expenses for the children?

Think about fairness. It is not fair for the children to go without—or feel guilty about needing—things that come up unexpectedly, such as medical treatment, school supplies, or sports equipment. Neither is it fair for one parent to shoulder all the burden because the other parent says, “I’m only paying exactly what the child support order tells me I have to.” Your divorce agreement should specify who’s paying for what, and in what proportions.