Haha, i heard that joke before.
Here is one-
One day a little girl came running up to her mom with 5 dollars in her hands. When her mom asked where she got the 5 dollars, the little girl said "Johnny paid me 5 dollars to do a cartwheel while he was up in the tree" Her mother sighed, and said "Hes only trying to see your panties. Don't do it again."
The next day, the little girl comes running to her mom with another 5 dollars in her hands. Her mother says "Oh no, You didn't do a cartwheel for johnny again, did you?" so her daughter says "I did, but this time I tricked him. I wasn't wearing any panties."