autosodomy 

The act of a male inserting his penis into his own anus.

"There's nothing worse than those goatse pictures!"

"You think so? You obviously aren't acquainted with the art of autosodomy."

autosodomy by Odiumjunkie April 23, 2005

autosodomite 

Someone who fucks their own ass.

"Ted, what are you doing?!"

"Fucking myself in the ass."

"Goddamn autosodomite..."

autosodomite by Z! September 20, 2006