Its wrong to physically hit a relative.
Jonah is at his brother Al's house in the summer and Al pulls a prank on Jonah by soaking him with a water balloon.
Jonah wants to react to being soaked.
Jonah tells Al that he got him this time but that he better watch out Jonah will get him back.
Jonah runs up to Al and swings his fist into Al's face, knocking Al to the ground.
Al laughs along with Jonah and tells him that he looks forward to seeing what Jonah will come up with in retaliation.
Al is shocked that Jonah would resort to violence and cowers in fear of being hit again.