[Jimbuna]

A man bought a lie-detector robot that slaps anyone who tells lies. Taking it home, he decided to test it on his schoolboy son.
'What did you do this afternoon?' he asked him.
'I did my homework', his son replied. The robot slapped him.
'Alright, alright- I went round my mate's house to watch a film!'
'What did you watch?' his dad asked.
'Toy Story', his son replied. The robot slapped him again.
'Alright- we watched porn!'
'Porn? When I was your age I didn't even know what porn was!', his dad exclaimed. The robot slapped him.
Then his wife said 'Ha! He's certainly your son!' The robot slapped her.
The robot is now up for sale.