John was a sucker for any new gizmo. His wife Marsha had long ago given up trying to get him to change.  One day he came home with a robot that he claimed was actually a lie detector machine.

At 5:30, their son Tommy returned home from school 2 hours late.  John asked: "Where have you been? Why are you 2 hours late?"

"A few of us went to the library to study," said Tommy.  The robot walked over to Tommy and slapped him, knocking Tommy to the ground.  "Son," said his father, "this robot is a lie detector; now tell us where you really were."

"We went to Bobby's house and watched a movie."

"What did you watch?" asked Marsha.

"The Ten Commandments", said Tommy.  The robot went over to Tommy and once again slapped the snot out of him.

Tommy got up and said: "I'm sorry I lied. We really watched a DVD called 'Sex Queen.'"

"I'm ashamed of you son," said John . "When I was your age, I never lied to my parents.  

The robot walked around to John and whacked him.  Marsha started laughing and said: "Boy did you ever ask for that one! But you shouldn't be too mad with Tommy. After all, he is your son!"

The robot walked over to Marsha and knocked her out of her chair.