An action in which a friend of yours prevents you from getting laid and then goes ahead and has sex with the same girl that he just cockblocked you from.
Friend 1: Yo is your friend gonna bang that girl tonight?
Friend 2: Nah, I'll be pullin' a geno and fuck her later!
Friend 2: Nah, I'll be pullin' a geno and fuck her later!
by glen ave January 2, 2011
Get the pullin' a genomug.