Boy has Tenticles

Boy was sitting on the toilet the other day and said, "Mummy, look at my penis."  He lifted up his penis to reveal his scrotum and testicles in all their little glories. 

"Yes?  What about it" I asked. 

"What's this thing?", he asked, giving them a little shake. 

"Those are your testicles and the skin around it's called your scrotum (we're all about proper words for bits around here)", I replied, wondering why he had never discovered his balls before now.

"Tenticles?  I have tenticles?  Cool."