After a low-key dinner at NYC hotspot The Darby on Friday night, Kim Kardashian and her hubby Kris Humphries jetted to Las Vegas to continue her 31st birthday celebration.

Clad in a white curve-hugging number with sheer panels, the Keeping Up with the Kardashians star joined her mom Kris Jenner, sister Khloe and her husband Lamar Odom and Kim's friend (and former Dancing with the Stars partner) Mark Ballas in Sin City on Saturday.

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First the group sat for a quick dinner at LAVO, where they dined on a spread of the Italian restaurant's specialties including their Kobe meatballs with tomato sauce, chicken parmigiana, veal, steak and Ceasar salad. They toasted the birthday girl with Midori Sour cocktails and champagne.

Next they headed to Marquee Nightclub inside The Cosmopolitan of Las Vegas, where Kim and her group sat at a VIP table surrounded by a packed house.

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"I can't believe [Kim is turning 31]! I feel like she's still my 5-year-old little girl with pigtails," Kris Jenner told Us Weekly on the red carpet outside the space. "I get very emotional when it's their birthdays. You know I feel so close to them but the time is going by so fast."

Kim was presented with a cake from Gimme Some Sugar that was in the shape of her and her hubby Kris sitting in a white Ferrari with a custom Kardashian logo on the car.

Khloe grabbed her sister for a dance before jumping on the mic to deliver an expletive-laden cheers to the birthday girl and leading the room in singing "Happy Birthday."

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The Kardashian klan left wrapped up their night at around 2 a.m.

"Tonight was so much fun!!! Yummy meal at Lavo then fun night at Marquee! Thanks to everyone who came out! Now jetting back to LA!" Kim tweeted early Sunday.

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