Duchess Kate, Camilla Eat 'Naughty' Sweets on Store Visit With Queen Elizabeth

Three queens walk into a London department store ...

On Thursday, Duchess Kate hit London department store Fortnum & Mason with stepmother-in-law Duchess Camilla and grandmother-in-law Queen Elizabeth. Arriving in the queen's Bentley, all three women wore different shades of blue: Camilla in navy, her majesty in eggshell blue, Duchess Kate in a fall-winter 2010 Missoni coat, accented by two daffodils to commemorate St. David's Day.

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Although it was the trio's first official public duty performed en masse -- part of the Diamond Jubilee schedule, celebrating the queen's 50th year on the throne -- Kate, 30, Camilla, 64, and Elizabeth, 85, were like three girls in, well, a candy store!

A source inside the shop reveals that Kate went straight to the chocolate counter (which she called "the naughty counter") in the newly restored food hall and confessed to the staff, "Oh, I love chocolate. Yes. I think most girls like chocolate"

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Prince Charles' wife, Camilla, meanwhile, tucked into a bag of gourmet jelly beans nearby. "What a treat!" she cooed.

Queen Elizabeth, however, abstained from all sweets during the visit -- but did join a tea party at the store with 150 staff members, and checked out a cake commemorating the renaming of the store restaurant to The Diamond Jubilee Tea Station.

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"They thoroughly enjoyed the visit," a source says. "Kate bought some Fortnum & Mason dog biscuits for Lupo."

During a plaque unveiling outside, "Kate was standing by Camilla the whole time, making sure not to get in the way of the queen. She seemed a little quieter than usual, taking lead from Camilla the whole time."

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