While fucking your girl, quickly put it in her ass and get in a couple of good bangs. When she turns around to say "What the FUCK!" - drop a smoke bomb and get the fuck out of Dodge!
I pulled a Filthy Ninja on my girl last night and the room still smells like sulphur.
by ACE666 January 29, 2008
A covert activity which involves sneaking into a room where a couple of people are engaged in love making, then jerking off to the live show, undetected of course.
Last night I caught Paul bangin' his bitch in my bedroom so I pulled the filthy ninja on em'.
by The Odor January 10, 2006