A wet, flaccid penis, usually after it's been freshly removed from a vagina, mouth, or rectum; thus resembling a slimy little slug. Can be the cause or consequence of ending sex.
(May also be used in verb form - see below)
To everyone's horror, Chris walked out of the bedroom naked with a satisfied expression and an exposed banana slug.
"I wouldn't have stopped pounding her yet, but my drunk was wearing off and I was pretty much banana slugging it by that point."
February 03, 2010