We had friends who had a difficult child, and who really knew how to pull their chains. He once hit his mother so hard he broke her glasses. They would visit us occasionally, and the kid would invariably take a swing at me. I would always stop the punch before it connected, and he would settle down and talk to me and basically be very well behaved. UNTIL his parents noticed him again. Then the misbehavior would start all over again. With me, he would be a sweet little boy, but for Mom and Dad, no way. I think it was due to inconsistent behaviors of the parents - Dad would try to be fairly strict, Mom was a pushover - and each overcompensated for the attitude of the other.
We moved and have since lost touch with the family - I would like to know how the little guy turned out.