An American tourist in London skips his tour group to explore the city on his own. He wanders around, seeing the sights, and occasionally stopping at a quaint pub to soak up the local culture, chat with the lads, and have a pint of warm beer. He even samples a doner kebab from a greasy takeaway.
After a while, he finds himself in a very high class neighbourhood... big, stately residences, no pubs, no shops, no restaurants, and worst of all... NO PUBLIC TOILETS and a familiar ominous feeling on his bowels and a churning in his stomach.
He desperately has to piss, poo and throw up. He finds a narrow side street, with high walls surrounding the adjacent buildings and decides it's ideal.
As he starts to lower his trousers he is tapped on the shoulder by a copper, who says, "Sorry, Sir, you simply cannot do that here, you know." "I'm very sorry, officer," replies the American, "but I really, really HAVE TO GO, and I just can't find a public restroom."
"Ah, yes," said the Bobby..."Just follow me". He leads him to a back "delivery alley", then along a wall to a gate, which he opens. "In there", points the Bobby. "Relieve yourself... anywhere you want."
The fellow enters and finds himself in the most beautiful garden he has ever seen. Manicured grass lawns, statuary, fountains, sculptured hedges, and huge beds of gorgeous flowers, all in perfect bloom. He pisses against a statue, throws up all over the lawn and explosively shits diarrhoea into the fountain.
As he passes back out of the gate, he says to the Bobby "That was really decent of you... is that the famous British Hospitality?"
"No," replied the Bobby, "that is the Russian Embassy." | 
