metamasturbation 

When you masturbate to a porno within a porno.
For example, when you are watching a porno and suddenly realize that the porno that the characters in the porno are watching is hotter than the porno that they themselves are doing.

Creeper 1: Dude, did you watch Ass Adventure IV yet?
Creeper 2: Yeah, but I don't remember anything from it. I ended up doing some metamasturbation when the girlfriend put on that video in the living room to get herself in the mood.

metamasturbation by St.Grizzly May 18, 2011

Metamasturbation 

Masturbating to a video of yourself masturbating

Metamasturbation
Dude I just metamasturbated last night

Metamasturbation by Tjom Neuman December 19, 2017

metasturbation 

Metasturbation is the practice of masturbating while thinking of yourself masturbating. This can be achieved simply through thought, or with mirrors or previously recorded photographs or videos of yourself masturbating.

"Dude, I walked in on my roommate metasturbating. He was blowing his load on a picture of his own face."

or

"Gosh, I love metasturbation. It's almost like getting myself off two times at once."

metasturbation by Dry Nasty October 28, 2011

metasturbation 

When one fills a piece of his or her thought, art, or conversation with constant references to painstakingly woven fictions with their own embedded culture, language, fiction, etc.

The dialogue was fine but the plot was all metasturbation.

metasturbation by Bob Dobbins May 28, 2009