fart flap 

The triangular rear side window in some smaller cars having a hinge on the front edge and a latch on the back edge that opens about 2 inches.

That fart is horrible! Open the fart flaps!

fart flap by Lord Windowsmear June 29, 2014

Fart flapping 

When a female uses a vibrator so powerful it causes the vaginal lips to slap each other causing the lips to make a "fart" sound.

Sarah: hey Jen did you use the penetrator 6000 last night?

Jen: yeah it literally caused me to fart flap it was hilarious.

Sarah: oh Jen you love abit of fart flapping.

Fart flapping by nipsmandem May 18, 2014

Fart flapper

The act of placing your nut sack over another's anus and letting your balls flap as they expel gas.

Nate come here. I want to do a fart flapper!

Fart flapper by Flap master June 17, 2013

Fart Flaps 

Butt cheeks.

That one passed right through the fart flaps.

Fart Flaps by TheBanchou July 8, 2017

Fart flaps 

When a man gets so old that when he lays on his back his balls cover his ass hole

"Dude I woke up last night laying on my back when I farted so hard my fart flaps landed on my stomach, they are suppose to be snug under my dick"

Fart flaps by GnTMoose July 14, 2020