Flopping Off 

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!

Flopping Off by Fatty Blumpkin March 17, 2015

flapping off 

One who plays flappy bird hard core usually with a record over 100

Mary: Will blew me off again last night!

Donna: Yeah he was flapping off again

flapping off by Speed kills January 26, 2014

Flipping Someone Off With Your Thumb 

It means you want to engage in sexual acts with the person. Instead of only using your middle finger to give someone the bird, adding your thumb let’s said person know you want to get it on with them.

Kyle: *Flips girl off with thumb*
Girl: “He flipped me off with his thumb. He wants to fuck! Flipping someone off with your thumb means they want to do it!”

Flipping Someone Off With Your Thumb by smile.dog.exe.1616 November 16, 2020

flipping it off 

Female masterburation

flipping it off in the toilet or bedroom

flipping it off by The Son Of God January 13, 2021