The Scorpion and the Frog

I told the kids the parable of the scorpion and the frog. which you may remember from the Crying Game.
If you don't remember that scene, allow me to recap:
A scorpion wants to cross a river, but not being able to swim, asks a frog to give him a ride on his back.  The frog says, "If I let you climb on my back, you will surely sting me."
The scorpion replies, "That wouldn't be in my interest.  If I sting you, we both will drown."
The frog thought about this and agreed to help the scorpion.  The latter climbed on his back and he began to swim across the river.  Half way across, he felt a terrible, screaming pain in his side.
"You have stung me!" he shrieked.  "Now we both shall drown!  Why did you sting me?"
Replied the scorpion, "I couldn't help myself.  It's in my nature."

Then I tucked Emma in, and went into Oscar's room and did the same.  "Don't tickle me!" he said.
"Why would I tickle you?" I asked.
"Because it's in your nature."