A man bought a lie detector robot that slaps people who lie. He decided to test it at dinner.

Dad: Son, where were you today during school hours?

Son: At school.

The robot slapped the son, and he immediately changed his story.

Son: Okay, okay, I went to the movies!

Dad: Which one?

Son: Harry Potter.

The robot slapped the son again!

Son: Okay, okay, I was watching porno.

Dad: What? When I was your age, I didn't even know what porno was!

The robot slapped the dad!

Mom: Hahahahaha! After all, he's your son!

The robot gave the mom a hot, dirty slap.