When you are fingering a girl and she is recieving no pleasure, you simply stick your whole arm in the vaginal cavity and twist, but you must say "oy the MCDUST TWIST"
Mike: Yo bro what you do last night?
Steve: Dude brah like i was fingering Sherryl last night, adn she didnt get pleasure, so i Mcdusted the shit out of her!
Mike: Did she bleed?
Kevin: Yo my chick was so horny last night, I gave her the ol' McDust Twist
Charlie:Ohhhh I like