I had a short spell on guard at Buckingham Palace in the days when the sentry boxes were outside the railings on the pavement. Young ladies would stand alongside us to have their photographs taken, then, knowing that we were obliged to stand motionless, thrust a hand into one of our trousers pockets and give us an almighty squeeze. There was no laughter but certainly a change of expression, sometimes with tears. Subsequently trousers pockets were sewn up, later the boxes and guards were moved onto the forecourt behind the railings.