assturbation 

To pleasure the anal cavity of oneself with the intent of sexual gratification.

I really wanted to go down on her last night, but when I got home she was in the middle of an assturbation session to the new Justin Timberlake video.

assturbation by decamel August 28, 2013

Assturbation 

Masturbation focused on pleasuring the butt, whether it be by massage or insertion.

Wow, this banana is frozen rock solid. I'm gonna have a good assturbation session tonight!

Assturbation by Twiggins Q. Neugebauer June 20, 2011

assturbation 

Masturbation restricted to the ass region. Usually performed by placing dildos, buttplugs, fingers, toothbrushes, or whatever else may be handy into the anal cavity. Lube is optional but highly recommended.

Suzy had never considered assturbation until she overheard Julie talking to Maria about shoving a 9 inch vibrator up her ass while fantasizing about Tom (Suzys dad).

assturbation by mindrape November 16, 2005

Assturbation 

Taking a shit while browsing porn that you will then proceed to masturbate to.

Perry: How was your day yesterday?
Gavin: Great, I had a real nice assturbation session.

Assturbation by RobotLunchbox December 8, 2016

Assturbation 

The penetration of the asshole

“I like assturbation, da Wayne likes to see me penetrate my booty whole”

Assturbation by Flecha January 23, 2019

assturbation-fueled car 

The homosexual counterpart of the masturbation-fueled car. It is a car that has been painted in all sorts of gay pride colors, symbols, and slogans, and is driven by a gay man or lesbian in hopes that he/she will get as many gay lovers as desired.

Why just look at that faggot asshat in the assturbation-fueled car over there!

assturbation-fueled car by Mark H July 15, 2004

double assturbation

See "double anal tug"

A sexual act in which two women (or men, whatever the preference) simultaneously jerk off an erect male using both of their asses with the penis in between the four ass cheeks, long-ways along both ass cracks.

Being the booty lover that he is, Stan likes to get a couple of big assed girls, oil up their thick booties, and get them to jerk him off using the ol' double assturbation technique.

double assturbation by actionman777 April 2, 2010