Little Johnny came home from school and asked his dad,
"Dad, I heard some kids talking about a thing called a vagina. What is a vagina, and what does it look like?"
Johnny's father is a bit surprised he has to start the sex talk this early with Johnny, so he decides to answer the last part of the question first - to ease into the conversion. So he says,
"Well son, before sex it looks like a beautiful unopened rose, glistening in the morning dew."
Impressed, little Johnny askes excitedly, "Wow, what does it look like after sex?"
The father thinks for a second and says,
"Well son, have you ever seen a bulldog eating a bowl of mayonnaise?"