The 28-year-old reality star took some time out of his busy schedule to make a guest appearance at a lucky fan's sweet 16 party at Marquee in NYC over the weekend and Life & Style has all the details on the luxe event.
"He came as a surprise to the party on April 21 and when he arrived at 10 p.m., the teenagers went crazy!" an eyewitness tells Life & Style.
And the birthday girl, Ashna, who is a huge Kardashian fan, got an extra surprise!
"Scott brought Rob [Kardashian] with him to partake in the festivities, too," the eyewitness says. "Scott figured he would surprise one of his biggest fans on her birthday."
"He toasted with a tower of sparkling cider and then got the party going," the eyewitness adds. "DJ Twist was spinning and all the kids got Sukitz lollipops, which are for energy, so they were going wild!"
While Scott was only asked to stop by briefly, he ended up partying with the kids for two hours!
"He was dancing and posing with everyone at the party," the eyewitness tellsLife & Style. "Kim and Kourtney were at a restaurant around the corner, but Scott stayed at the sweet 16."
Perhaps the lucky birthday girl will have the party for her 17th birthday at Scott's new restaurant, Ryu, in NYC -- it opened last night!