Three black penises
 

At an art exhibition, a couple was viewing a painting of three VERY naked, VERY black men sitting on a park bench. What was unusual was that the men on the ends of the bench had black penises, but the man in the middle had a VERY PINK penis.
While the couple was scratching their heads trying to figure this out, the artist walked by and noticed the couple's confusion. "Can I help you with this painting?" he asked.
"Well, yes." said the gentleman. "We were curious about this picture of the black men on the bench. Why is it that the man in the middle has a pink penis?"
"Oh," said the artist. "I'm afraid you've misinterpreted the painting. The three men are not Africans, they're coal miners, and the fellow in the middle went home for lunch!"