Backstreet Boys fans were in for an unforgettable night on Aug. 21 at The Barbershop Cuts & Cocktails in The Cosmopolitan of Las Vegas. Ahead of the band’s buzzed-about shows at Sphere Las Vegas, boyband member Howie Dorough surprised the crowd with an impromptu performance as part of his birthday celebration.

Dorough welcomed turning 52 at the stroke of midnight on Aug. 22 at The Barbershop. Dorough has a lot to celebrate, one reason being the boyband announcing the extension of their massively successful “Into the Millennium” Sphere Las Vegas residency, first with dates in December, then additional performances next February.

Joined by his wife, Leigh Boniello, and a group of friends, Dorough was presented with sparklers as the band The Regulators led the bar in singing “Happy Birthday” inside The Cosmopolitan hotspot.

The Backstreet Army, the band’s ardent fans, were out in force and received a massive surprise when Dorough joined onstage to sing iconic hit “I Want It That Way.” Guests sang along word-for-word while Dorough soaked in the love from fans who had no idea the global superstar would be making an appearance.

The Regulators, the powerhouse band with members who have performed with acts including Lifehouse and Savage Garden, features guitarist Ben Carey, vocalist and bassist Bryce Soderberg and drummer Al Serrato. Together with Dorough, they turned the night into a full-scale celebration.

Before heading inside, Dorough honored the Barbershop tradition of sitting in the barber’s chair of the popular men’s grooming salon, which serves as the entrance to the hidden bar. Throughout the night, Dorough could be seen smiling from ear to ear during his birthday celebration.

Known for its swanky speakeasy vibe and nightly live rock, The Barbershop has become a magnet for surprise performances, Bruno Mars, Anderson .Paak, Sir Rod Stewart, Machine Gun Kelly, Sammy Hagar and Zac Brown among them.