Britain's Prince William and girlfriend Kate Middleton booked a romantic break under the names Mr. and Mrs. Smith.
The couple spent the weekend in Fowey, Cornwall, after Kate decided to organise a romantic 27th birthday treat for the prince.
A source said: "They have been staying at private house under the assumed name Mr. and Mrs. Smith.
"It is quite funny, really, that they feel they need to go to such great lengths to keep their visit a secret - but I suppose it adds to the romance."
Despite planning a romantic break, the couple was joined by William's brother Prince Harry and several other friends, who forced them to cancel their intimate dinner for two in favour of an alcohol-fuelled beach barbecue.
The source added to Britain's The Sun newspaper: "William and Harry spend a lot of time in Cornwall in summer. They love it. They are mad about surfing and can go to secluded beaches where they can go surfing largely unnoticed. But this time word quickly spread they were in the area."
Meanwhile, William is reportedly planning to take Kate on his family's annual visit to the Queen's Scottish estate Balmoral, fuelling speculation they are planning an engagement.
It is the first time Kate has been invited on the hunting break on the August bank holiday weekend, though she has met the monarch - William's grandmother - before.
A source said: "Kate loves shooting so she will fit in well with the Royal Family. She will take it in her stride."
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