One who masterbates furiously while defacting.

To simultaneously poop and masturbate. My friend Daniel, who is undoubtedly a chronic poopsterbater, coined this phrase.

the act of masturbating while defecating simultaneously.

Invented in the year 10,567 BC by a scribe named Rich Siegel, this form of self-amusement has a long storied yet secret history. Sort of like the Masons and their lore, but people don't talk about it as much. From ancient times, people have been sexually aroused by their own poop and pleasured themselves in various ways while pooping, to further enhance the experience.

when masturbation is done while taking a poop

To simultaneously poop and masturbate.

Alabama Hot Pocket, and to Poopsterbate at the same time. You start to Poopsterbate, and when you shit, you separate a girls vagina lips, and shit in it. Then you fuck her with your cum wet dick.