IT MUST HAVE STARTED BEFORE 1973 AS THAT'S WHEN I FIRST SEEN IT DONE.
WHILE WATCHING A MOVIE ON THE SIDE OF A VEHICLE WITH A WHITE SHEET AS A SCREEN, TWO FELLOW CANADIAN SOLDIERS AFTER TOO MUCH IN THE WAY OF DRINK, STREEKED AND THEN STOPPED AND MOONED US ALL IN EGYPT. I DON'T KNOW WHAT WAS FUNNIER, THE PART WHEN ONE TRIPPED AND FELL OR THE LOOK ON THE POLISH OFFICERS FACES THAT WERE PRESENT AT THE TIME.
BOTH ENDED UP IN THE KITCHEN FOR THE NEXT TWO WEEKS HELPING OUT IF YOU KNOW WHAT I MEAN.
.......PBA