Kourtney Kardashian Celebrates 36th Birthday in Sin City With Scott Disick

— -- Kourtney Kardashian traveled to Sin City this weekend to kick off her 36th birthday bash.

The eldest of the Kardashians Instagrammed a photo of herself and two friends at 1OAK night club, where she and boyfriend Scott Disick partied on Saturday night.

While the rest of the Kardashian sisters didn't make it out to Vegas, the family hosted a belated celebration complete with a cake made by Kris and card from Khloe.

The card read: "To the best, finest, grooviest, most on fleek, bad ass, MILF, bootyliscious, sister in the world!!! You are the ying to my yang, Siegfried to my Roy, Sonny to my Cher and the Ricky to my Lucy! I love you more than I could ever ask for!"

Kardashian shares three children with Disick -- son Mason, 5, daughter Penelope, 2, and son Reign Aston, four months.