Half the hand, then ball your hand into a fist, make sure you don't have any rings or watches on. Use lube, like crisco or lotion. Then massage the anus. Make sure to go to the bathroom and clean out...
Fist pumping is when a group of guidos get together and hit the club. Once they're there, they stand in a circle, and swing their fist up and down to the beat of the music.