The Lie Detector Robot!
A man bought a lie detector robot. Every time the robot detects a lie, it slaps the liar.
He decided to test it at dinner on his son, who he suspected of often lying to him.
DAD: Son where were you today during school hours?
SON: "At school." Robot slaps son. "Ouch! Okay okay, I went to the movies!"
DAD: "Which one?"
SON: ''Harry Potter'', Robot slaps son again. "Ow! Okay, jeez - I was watching an adult movie, okay?"
DAD: "What?? When I was your age I didn’t even know those existed!" Robot slaps Dad.
MOM: "Ha ha ha! He's your son, after all!"
Robot slaps mother.