plum bag
The often goose-bumped, sometimes reticulated, sack o’ skin suspending the testes at a controllable distance from the groin so as to maintain temperature equilibrium, because the little spermatozoa inside don’ like bein’ too hot or too chilly. Scrotum, ballbag, nut sack, coin purse.
“If you don’t do what I tell you right now, your plum bag will be my hacky sack.” -- Vanessa Marcil as Samantha Jane on Las Vegas episode “Run, Cooper, Run”