Inserting one's penis rectally, and proceeding to rub the tip of one's phallus around female's lips in a swab-like fashion. Preferably while wearing a thick, goofy, uncoordinated sweater while holding a sandwich, to emphasize the Cosby effect.
The green/brown shade of her upper lips indicated to me she was an expert in the art of the Cosby Swab. She made me drop my hoagie.
by drphilsboner October 20, 2008