I agree that kids need to learn valuable lessons, but is this important enough for the fight. I mean if this is par for the course with this kid, and he really NEEDS to have the point driven home fine. However, think about the true effects of your actions. Are you going to drive a wedge between you by doing this or are you the man in his life that needs to teach him this lesson? Think about your relationship with him...maybe the person you need to ask is your sister.