"No, don't worry, I've been on one of these before. In 1979. It was splendid. Hopped on at Green Park station to celebrate the opening of the first part of the Jubilee line and the bally thing actually went underground! Couldn't believe it! Thought Daddy had been pulling my leg. Marvellous. Of course, my valet got on half an hour before and wiped down the seat. I presume someone's done the same this – oh, they haven't? Ah. Well, not to worry. I'll just burn this suit when I get home."
Such is the conversation we imagine must have passed between Prince Charles and those who ushered him, 33 years after his first and hitherto only trip on the London Underground, into the remarkably uncrowded carriage taking him from Farringdon to King's Cross station to mark the 150th anniversary of the tube.
Meanwhile, Camilla can only be sitting there thinking: "Bloody hell. I thought it was going to be gilded coaches all the way. Should have stuck with Andrew PB. At least he drove his own Bentley."
So, what do you think was running through the royal couple's minds?
