Flap Stack 

The act of two guys double penetrating a girl by having the girl sitting face forward on one guy (reverse cow girl anal style) and being vaginally penetrated by the other guy facing her.

Michael and Cory totally flap stacked that girl from their acting class.

Flap Stack by giraffeafrass October 11, 2010

Flap Sack 

Loose skin on your balls do to tiny nuts

Man mark temple has some flap sack showing through his shorts ..!

Flap Sack by Flap Sack April 22, 2021

Fapstack 

A pile of (usually adult) magazines in a man's bathroom.

Man, Mike has one of the most epic fapstacks I've ever seen. Didn't want to leave the shitter for an hour!

Fapstack by Lolfast January 27, 2011

flapsmack 

when two larger folks screw, it's the sound of their bellies that you hear

FLAPSMACK. FLAPSMACK. FLAPSMACK. FLAPSMACK. Oooh. Oooh. FLAPSMACK. FLAPSMACK. FLAPSMACK.

flapsmack by marinara82 February 20, 2011

flapsack 

A condition most often brought about immediately following a rather formidable ejaculatory event.

It will generally cause ones scrotol-sack to appear deflated, flappy and saggy.

The condition typically resolves itself in 8-12 hours once the owner of the flapsack has had the opportunity to replenish his bodily fluids and what not.

Tyrone to his partner: Man homegirl Shwatanquerayray done wore me out bro....she done left me with a flapsack el grande yo.

Lucious in response: Ahhhhh yeeahh homegirl be knowing how to operate her body fo sho. You best get some gatorade or coolade up in ya for the dehydration mane.

flapsack by Shit Fkcuer Deluxe September 5, 2013

Flapstick 

An uncircumsized penis.

Justin Bieber is a flapstick.

Flapstick by ferngullyfan March 15, 2011

Flabstacks 

An insult originating in Hull and now spreading across england referring to someone who is either very fat or someone you want to call fat.

"Hello Roan"
"Oh get lost Teal ya flabstacks"

Flabstacks by Harry Smidge April 13, 2010