A new machine came to market, one that smacks those who lie. The father decides this could come of use, and decides to purchase it and takes it home.
A little while later, the principal calls telling him that his son skipped school. Outraged, the father confronts his son.
The dad scoffs, "Son! Where were you during school hours today?"
The son then replies, "At school!" to then be slapped by the machine. "Ow! Okay I lied I was at the movies."
Furious, the dad asks, "Which one?"
Mark then replies, "Harry potter." He's slapped again and says, "FINE it was a porno."
Surprised the dad exclaims, "...at your age I didn't even know what a porno was." The machine slaps the dad.
Watching it all unfold, the mother comes in and chimes in and says, "Hahahaha, after all he is your son." The machine gives her a hot, dirty slap.