it comes from japanese sexual practice whereby a man inserts his penis into the quivering touchhole of a live duck. the duck's head is then lopped off and in the final moments of its apparently futile life, the anus spasms. the same principle is used by japanese hookers where they dunk their heads in tubs of water while sailors penetrate their twitching love sockets with their filthy, uncut sushi rolls. another reason to travel japan!
after a long night of munging for bean juice, i decided it was time for a duckjob.