A sexual act where the male ejaculates into his own hand and then vigorously and most unexpectedly slaps his partner in the face with the goo filled paw. Typically used in conjunction with the rusty trombone
however can be incorporated into just about any exciting encounter.
She had her tongue buried so far up my ass I exploded into my hand, what was I to do with a fist full of giz? Had to give her the big finish.