ESH. And the kids will be the ones to pay because you are both acting immature and letting the kids suffer for it. I don’t care if it’s my worst enemy’s kid, that kid doesn’t get punished for it or used as a way to punish another. That kids mother is ill, I don’t care that you hate the mother but have some compassion for a child who is also your own child’s sibling whom you are teaching to hate by example and sort out your problems in a way that doesn’t cause even more damage to those innocent ones caught in the crossfire. Poor choices have been made. Don’t continue making them. Take steps to live a life less filled with hatred and resentment.