Wearing a figure-hugging (what else?) sequined cream-colored dress, the former Mrs. Kris Humphries, was the star attraction on the red carpet.
Hosting their own birthday parties in Vegas is big business for the Kardashian clan but maybe Kim just needed a night of fun as her divorce/annulment case drags on.
Dancing with the Stars alum Rob was also joined by his mother, Kris Jenner. She was such a party animal, at one point Kim tweeted http://twitter.com/#!/kimkardashian "mom gone wild!"
His teen half-sisters, Kendall and Kylie Jenner were part of the scene for an earlier dinner.
At 3 am, they all the Kardashian-Jenner womenj piled into a private jet and headed back to L.A.