Lie detecting Robot

Rahul's Dad brought home a robot one day. The robot had the ability to detect lies and would slap the person who lied.
Rahul returned late from school. Dad asked, "Son why are you late from school?"
"Dad, we had extra classes today". Robot slapped Rahul on his face.
Dad shouted, "Come on tell me the truth, why are you late?"
"Dad, I went to see the movie Ten Commandments." Robot slapped Rahul on his face.
Sorry dad, I went to see the movie "Chameli Ki Jawaani".
"Shame on you son, when I
was your age, I never watched obscene movies or misbehaved."
Immediately, Dad gets a slap on the face from the robot. Rahul's mom comes walking out of the kitchen and says to her husband,
"After all, he's your son!"
The robot slaps the mom. -
OOPS ..!!