Sack Flapping

The sound your ballsack makes when pounding a tight slizz from behind; a good sack flap goes to a beat and makes a soft thumping noise... & can lead to minor bruising and irritation of the stomach region of the partner whos tight slizz or smelly balloon knot is being ravaged

Kelly: "Whats that on your stomach?"
Sara: "I had a good Sack flapping last night"
Kelly: "Oh i got sack flapped last wednesday; and his beanbag bruised the hell out of my tummy "

a raging sack of cunt flaps

Someone who is even more heinous than a cunt, because “cunts are still useful”.

What a raging sack
Of cunt flaps!!!

Or, Ed is a raging sack of cunt flaps.

Flap Sack

Loose skin on your balls do to tiny nuts

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

Sack Flaps

Sack Flaps are a rare genital disease that gives the unlucky victim an extra, saggier pair of nuts. This extra pair usually hangs lower than the typical pair.

Hey bro, do you have sack flaps!?? I could see them through your thin leggings.