When anyone says just kidding, and they've really said something insulting, I just visualize myself placing a call to the IRS to let them know that this person is defrauding on their taxes, then I go and do it, and to make sure they wind up in federal prison, I make cash donations to both political parties in their name with their address, accompanied by vitriolic hate mail. Then when they are dragged off to the federal penitentiary, I come to visit them behind the caged windows. When they pick up the phone to speak to me, I say, "Just kidding." Then I hang up and leave, remarking on what a wonderful sunny day it is outside.