Once upon a time a sailor ran into his doctor's office and begged him for 
help. He pulled down his pants and showed the doctor his dick, which was 
sporting a ruby red ring around the tip. He asked the doctor if there was any 
cure for this strange VD that had appeared.

The doctor just smiled, soaked a cloth in alcohol, and rubbed the end of the 
dick three times. The sailor looked down and saw that the ring was gone.

Ecstatic, he paid the doctor and ran off to catch his ship. A few months 
later, another sailor came to the doctor and said to him: "A few months back, 
my buddy came here with a ring around his dick, and he said you just rubbed 
it three times and he was cured. Well, I have a similar problem ..." The 
sailor pulled down his pants and showed off his dick, which was sporting an 
emerald green ring around the tip.

Well, the doctor just reached into a pocket, took out a large knife, and with 
one whack cut off the sailor's dick.

"What did you do that for!?" screamed the sailor in agony.

"Your buddy had lipstick around his dick," explained the doctor, "You had 
gangrene."