During a threesome, when a penis is inserted into one anus and re-appears covered in fecal matter, if the penis-wielder doesn't have the decency to clean said appendage before plunging it into either a mouth, anus, or a vagina, they are known form then on as a "Fudge Mule."

A pubic hair piece. A toupee for the pubic area/genitals. In the 1700’s when mercury was used to treat sexually transmitted diseases (Gonorrhea or Syphilis) one of the side effects was the loss of pubic hair. To disguise this condition, that was not cured by mercury, a Merkin was employed.