reverse grumpkin 

when a person sitting on a toilet taking a shit gives oral sex to someone standing in front of them

yeah i got a grumpkin then gave her a reverse grumpkin

reverse grumpkin by Bradford, PA March 18, 2011

reverse grumpkin 

Same as a a grumpkin...A girl is taking the shit while the guy eats the girl out!

man! that was a good reverse grumpkin!

reverse grumpkin by Joe Davis September 11, 2003

grossie grumpkins

The anonymous old man - most likely suffering from some form of dementia - who takes a shit in the sink of public restrooms

Don't go into the bathroom, Bob. It looks like Grossie Grumpkins struck again.

grossie grumpkins by Betty Wagaman October 15, 2006

Grumping it

When you skip a tutorial in a video game, and get stuck or lost in something the tutorial taught. A reference to Arin (Egoraptor) of the youtube channel Game Grumps, who would always skip tutorials.

"Bro, you're grumping it! You shouldn't have skipped the tutorial."
"Ah, yeah, I grumped it."

Grumping it by queephlosion December 16, 2020

Forrest Gumpkin 

Recieving oral sex from a retarded girl while taking a crap.

The waterhead with a hockey helmet on gave me a Forrest Gumpkin after she got off the shortbus.

Forrest Gumpkin by miller66 December 16, 2008

Grumping 

When a person grind/dry humps a person alive or dead

"Did you see tom and tracy grumping at jimmys party last night?" " dude I totally practiced grumping on my pillow last night."

Grumping by Og_grumper_69 August 1, 2017

Grumping 

The act of making an exaggerated frown in the shape of an upside down "U." Often used when someone is being ridiculed in a joking situation.

While grumping be sure to make your frown as curvy and unpleasant as possible

Grumping by mmoneh November 18, 2011