Shitturbate 

to masturbate while taking a poop.
Also used in the form shitturbating and shitturbated.

I can't believe you just walked in the bathroom and saw someone shitturbate at that party.

Shitturbate by Birdslur December 8, 2009

Shitsturbate 

To masturbate oneself while taking a shit. Simultaneous masturbation and defecation. The ultimate dual release.

After years of marriage, Carl's wife finally figured out her husband takes an excessively long time in the bathroom because he loves to Shitsturbate.

Shitsturbate by Eaton Holgoode April 28, 2016

shasturbate 

The act of masturbating while defecating.

I was in such a rush this morning that I was forced to shasturbate,.

shasturbate by vink pink February 10, 2005

Shitsturbation 

A simultaneous performance of shitting and masturbating, often done in public restrooms.

Kayla: Wow, I heard some really weird noises when I was using the restroom. Sounded like someone was really enjoying their dump...
Michael: They were probably undergoing Shitsturbation. It's like a self-performed blumpkin with your hands.

Shitsturbation by gofgirl983 December 17, 2011

shiturbate 

The act of masturbating while taking a shit.

Thomas missed the meeting because he decided to shiturbate.

shiturbate by Fuzzy Buttons December 15, 2013

Shiturbation 

The act of masturbation while taking a shit.

Taking shits are boring, so I decided try my hand shiturbation to make it more fun.

Shiturbation by hoovyoovy May 30, 2010

shaturbate 

To shit and masturbate at the same time

I was sitting on the toilet, and I decided to shaturbate to this picture of Jenny

shaturbate by Poloshirts64 May 7, 2014