A story I've heard in a London pub:

At Heathrow, a 300-foot long red carpet is stretched out to Air Force
One and President Bush strides to a warm but dignified handshake from
Queen Elizabeth II.

They ride in a silver 1934 Bentley limousine to the edge of central London
where they board an open 17th century coach hitched to six
magnificent white matching horses.

As they ride toward Buckingham Palace, each looking sideways and waving
to the thousands of cheering Britons lining the streets, all is going

But suddenly the right rear horse lets fly with the most horrendous,
earth-rending, eye-smarting blast of gastronomic flatulence ever heard
in the British Empire, including Bermuda, Tortola and the Falkland
Islands. It shakes the coach.

Uncomfortable, but under control, the two dignitaries of state do their
best to ignore the whole incident, but then the Queen decides that's
ridiculous. She turns to Mr. Bush and explains, "Mr. President, please
accept my regrets. I'm sure you understand that there are some things
that even a Queen cannot control."

George W. Bush, ever the gentleman, replies, "Your Majesty, please don't
give the matter another thought. You know, if you hadn't said something,
I would have thought it was one of the horses."