At a sharing session in a kindergarten class, a little boy announced, "My daddy has two penises."
The teacher was taken aback.
"Two?" she said before she could stop herself.
The little boy nodded vigorously. "He has one he uses to pee."
By now the teacher had recovered. "That's very nice," she said, "but we really shouldn't talk about...."
The little boy continued, "He uses the other one to brush mommy's teeth."
(Okay, the way I heard this one, it started with the teacher drawing a picture of a penis on the board. I'm no expert, but I'm pretty sure that only happens in Pervtown.)