Kim Kardashian Watched Mason While Kourtney Partied in Vegas

Credit: Denise Truscello/; Toby Canham/Getty Images

What happens in Vegas, stays in Vegas!

Although it looks like Kourtney Kardashian's birthday celebrations in Sin City were pretty tame. The reality star celebrated her 32nd birthday Friday night at the grand opening of Gallery Nightclub at Planet Hollywood Resort & Casino in Las Vegas.

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Kardashian was joined by boyfriend Scott Disick, 27. (The two have a 16-month-old son together named Mason.) She wrote on her official blog: "The club was amazing!! I could have people watched for days. Kim stayed home with Mason. It was her first night alone with him. They slept in bed together and had a slumber party."

The petite star wore a navy Contrarian dress with black Christian Louboutin pumps. An insider told Us Weekly she danced with friends and sipped champagne throughout the night. The highlight of the evening? Kardashian's birthday cake was presented to her with feather-flashing dancers.