Coalminer
A man sitting in a bar needed to relieve himself and went in the restroom.
He came back moments later with a bewildered look on his face and said to the bartender, "I just saw the strangest thing, a black man with a penis as white as snow!"
The bartender had to see this for himself and promptly went to the restroom to take a look. He came back out laughing.
"That's not a black man, that's a coal miner just back from the whorehouse!"