Johnny Fitzmacaroni II's definitions
A penis in which one would assume has recently been inside of someone's butt, judging by sight, smell, or taste.
"Whoa man, I think Jimmy has some serious butt-penis going on!" or "Whoa Jimmy, your dick tastes like some serious butt-penis!"
by Johnny Fitzmacaroni II January 13, 2009
Get the butt-penismug.