Under Training's definitions

fisturbating

To masturbate by inserting one's fist into one's own orifice or orifices. Artificial or disembodied fists may also be used. The word is a hybrid of "Fisting", "Masturbating" and "Sophisticated", and as such could be considered a sophisticated form of self-fisting.

"I wouldn't go in there Gavin, Tylah is Fisturbating."

Bryce: "Dan, if you don't sort that shit out my fist will be up your ass"
Dan: "I can fisturbate MYSELF!"

by Under Training May 11, 2008