Kate Middleton Stuns in High-Slit Dress at Thirty Club Dinner

Kate Middleton looked gorgeous and elegant in a fabulous gown, stunning earrings and unforgettable shoes as she arrived for a private dinner with her husband and advertising and media executives in London May 7. Is this her best look yet? VOTE!

Kate Middleton Dons High Slit, Jimmy Choos At Claridge's

KATE MIDDLETON DONS HIGH SLIT, JIMMY CHOOS AT CLARIDGE'S

In case you didn't get enough black tie dresses last night, here is Kate Middleton in a stunning high-necked Roland Mouret gown with a thigh-high slit and glimmery Jimmy Choos.

Seriously.

The duchess surprised us all with an unexpected outing tonight, arriving with Prince William to the swank Claridge's Hotel in Mayfair for a private function this evening. The event is hosted by the Thirty Club, an elite group of media players.

A royal aide told the Daily Express, "[The prince]’s been invited for about the last nine years but thought it right to accept the invitation this year as he has this personal landmark [his 30th birthday] coming up and it is such a landmark year for the Royal Family in general."

Kate Middleton stuns in sparkly white dress

So he and Catherine got dolled up and headed to Claridge's. Will was wearing his typical double-breasted tuxedo (seriously, can someone get him a new tux?). But Kate stunned us with a variety of surprises: a long-sleeve, solid white dress with a high neck, recalling Diane Kruger's 2010 Met Gala gown by Calvin Klein; bare legs (!); rather vertiginous, sparkling Jimmy Choo sandals; and red toes!

How sexy -- and yet still tasteful -- does Kate look with her tights off and her legs showing? (OK, we'll say it: she's almost Angelegging.)

We love this look for Catherine. Do you?