sack attack
Particularly vulgar and amusing variant on flashing by Greg, who would expose just his scrotum in public.
Sometimes this would be just casually doing normal stuff like, say, buying sweets at the shop with his scrotum hanging out of his flies as if he hadn't noticed, and sometimes it would be a full on run-up-to-the-granny-pull-the-old-sack-out-whilst-shouting-sack-attack-and-running-away-again routine. Endlessly hilarious and linked to several legendary tales.
written by ba*nsk* *, approved by Phil

A saucier variation of "sack attack" was the game of "Bollock". The point of "bollock" was to get as close to possible to your prey, with the jackpot awarded to those who get their bollock to rest on someone's leg.
A "bollock reversal" was terrible but fair, and involved the twisting of an exposed testis. A hit and run approach is advised.
written by ai*en cl*rks*n, approved by Log