Th'Lumpkin 

The sexual act of receiving fellatio while sitting on a toilet with a puffer fish in your ass. Essentially, it is a blumpkin with the addition of a puffer fish in the anus.

Bonus points are given for agitating a live puffer to the point of inflating and impaling the anus with it's spines during the act.

Max was never able to sit in hard chairs after Dave gave him a spiky Th'Lumpkin.

Th'Lumpkin by The Almighty Pig April 8, 2019

thumpkin 

Masterbating while taking a shit

dude my phone fell in the toilet while I was doing the thumpkin

thumpkin by bulwinkle April 11, 2007

Double Thumpkin

When you stick your thumb in the bumm and the love hole and alternate in and out in and out in and out as fast as you can making a noise like "nenenenene"

Tole threw trash out of the car when I told her not to so I gave her a double thumpkin.

Double Thumpkin by |fn|Gravyfury December 30, 2007

Muddy Thumpkin 

The act of jamming both your thumbs up a someones anus and proceeding to twiddle them around like you are using a game controller.

Person 1: Hey man are you still with your girl?
Person 2: Nah man she broke up with me after I gave her the ole Muddy Thumpkin

Muddy Thumpkin by xXPoonMonsoon69Xx June 3, 2016

Double Thumpkin

Placing the right thumb in the vagina, and the left thumb in the butthole.

My wife moaned and groaned as I gave her a no-lube double thumpkin.

Double Thumpkin by SlimGravy January 16, 2019

Thumpkin 

The act of masturbating while taking a shit.

While sitting on the toilet, waiting for the turd to drop, I took advantage of my alone time and gave myself a thumpkin.

Thumpkin by Davidtavis April 2, 2017

Thumpkin 

A more powerful blumpkin; a blumpkin with 'a little more umph.' A quickly and fiercely delivered blumpkin, often resulting in massive amounts of shit water and semen splatter with heavy collateral.

1. So my girl sat me down on the john and we proceeded to experiment with a blumpkin. It went downhill from there and I ended up getting more of a thumpkin than anything else. By the end of it, us and the whole god-damned bathroom was covered in shit and cum.

2. Yeaup, so I pressured Lisa into giving me a blumpkin the other day... bad idea. Instead I got a massive thumpkin that blew out the lights and shattered my mirror. The toilet's fucked too.

Thumpkin by mcautistic April 6, 2013