1 definition by Fatty Blumpkin
Auto erotic genital manipulation performed without the aid of one's hands. The flaccid penis is thrust about with aggressive hip movements and shuffling for between one and two hours or until erection occurs. The flopping off continues for another three to twelve hours when climax is finally achieved. Women with large clitori or labia minora may also engage in flopping off.
Guy 1: Man, I was flopping off like crazy yesterday. Took me like 13 hours but it was sweet, yo!
Guy 2: An all day floppoffathon? Gross!
Guy 2: An all day floppoffathon? Gross!
by Fatty Blumpkin March 17, 2015