The act of using your own cum to stick breadcrumbs (or sand) to your dick (via rolling) Then proceeding to slap the girl that made you cum (or another girl if preferred) across the face until it grows red or begins to chafe.

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.