The reality stars left their three children at home as they hit 1Oak Night Club at The Mirage Hotel and Casino on Saturday, 23 May to celebrate Scott's 32nd birthday.
Scott and Kourtney, 36, are known to love a good night out in Sin City: they partied there in February, while Kourtney went solo to Vegas in March and April.
But there were no Hangover-style antics for Kourtney, who stuck to drinking tea. She shared a picture to Instagram showing herself clutching a teapot while pals enjoyed frosted cocktails.
It was an early celebration as Scott didn't actually mark his big day until today, 26th May.
He told People he would likely have a chilled out birthday, perhaps barbecuing in the backgarden at home with Kourtney and the kids: Mason, five, Penelope, two, and Reign, five months.
It was a busy weekend for the Kardashian clan: while Kourtney and Scott were in Vegas, Kim was celebrating her one-year wedding anniversary to Kanye West, Khloe was flying to Dubai, and Kendall and Kylie were at the Monaco Grand Prix.
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