OP, when my child was younger, I made her practice math facts (multiplication tables, if I remember correctly), and she was less than thrilled with that. So she told me she wanted Dad to divorce me so the two of them would move away and live in their own house happily ever after

It was hard to keep a straight face but I told her somberly that, in case of a divorce, I'll still have joint custody and, despite her spending only half of the week with me, she'd have to study her math facts for twice as long as she does now to make up for lost time.
I don't think she quite got what 'joint custody' means, but she never brought up that creative idea again.