To insert your entire hand into the vagina and/or anus of another whilst holding a McDonald's hamburger sandwich, most often a BIG mac but in essence, any hamburger sandwich from McDonald's extensive menu would constitute the act of McFisty.
by fat.cunt.with.a.tiny.cock July 29, 2014
the act of fisting a girl/woman or boy/man by mcgillis while being extremely drunk, possibly after a night at Thursday in the square. This act is made possible by thrusting ones fist in a womans vagina or a gentlemans asshole.
by Olypapaya June 15, 2007
Whereby a person inserts their fist up a woman's ass after repeated close fisted punches to the anus. The effect is complete when the arm is inserted up to the elbow (lube optional, but appreciated). The free arm can be utilized to implement a donkey punch or a DELUX French Garden McFisty (when the off arm is inserted in a piston-like manner)
Some bitch at the music store talked back to me, so I punched her in the ass till I gave her a French Garden McFisty. She still wouldn't shut up so I donkey punched her.
by kyjohnson318 August 11, 2009