The Long and Short of It
A white guy is being shipped off to Jamaica for a year with the army. His fiance, Wendy, is really worried about her man being unfaithful, so she asks him to tattoo her name to his penis... He agrees, and does so.
When his penis isn't erect you can see the letters W and Y. The woman feeling secure knowing that her name is tattooed on her man's penis says good-bye to her fiance and he leaves for Jamaica.
One day, while in Jamaica, the guy is at the urinal and a black Jamaican comes and stands at the urinal next to him... The white guy happens to notice that the Jamaican also has a tattoo on his penis and he could see the letters W and Y, so he says to the Jamaican, "Wow, that's really interesting, I guess you have a girlfriend named Wendy too?"
And the Jamaican looks at him with a puzzled look and then stretches out his penis and it says... "Welcome to Jamaica have a nice day!"