1) i wanted to make my girlfriend feel merry in the bedroom this christmas so i decided to deck the balls
1) to festoon one's testicles with colored lights, evergreen garlands, and tiny christmas ornaments  2) to punch santa claus in the nuts for shortchanging you last christmas
"1) i wanted to make my girlfriend feel merry in the bedroom this christmas so i decided to deck the balls" What is the definition of "deck the balls"?