It's bad to involve your friends in your drama.
Jack decides to break up with Jill after finding out she cheated on him.
Jack wants the support of their circle of friends.
Jack leans on his friends for emotional support but doesn't begrudge them for remaining friendly with Jill.
Jack badmouths Jill to all of their mutual friends and asks them to turn away from her.
Jack manages not to pressure his friends into picking sides.
Jack loses the friends who disapprove of his actions.