My ex wife and I, both 45yo, have been divorced now for 7 years. During this time, our child has been on my health insurance. Our kid has braces, I pay for that also. The child is also with me at least 75% of the time. I obviously pay for clothes, food and the like. I work full time 8-5pm m-f. Ex wife is in restaurant industry, works evenings, schedule varies. I recently asked to start contributing to her health and orthodontics. She told me to fuck myself. She uses the "reasons" for our divorce is why she feels she doesn't have to pay. I do not pay child support. AITA for asking/insisting she start paying something towards these expenses? 