When you're
banging a girl doggy style and she's about to climax, grab her by the ankles, stand her on her head and
cram your fist down her
dank exit hole, thus ruining her orgasm.
Also see Inverted Particle Accelerator for more sexually deviant partners.
Hey man, why is your girlfriend walking so
funny?
I gave her the
classic inverted show stopper last
night and now her pelvis is out of alignment