Nick Jonas is the youngest brother from the ‘Jonas Brothers’ trio band. Most people probably remember him as being on stage singing all across the country as teenage girls fell in love with his smooth voice and nice looks. But, Jonas is all grown up now. He turned 21 on Monday and celebrated his big day in Las Vegas.

Olivia Culpo, Nick’s girlfriend, was in attendance for the celebration. His brothers, Joe and Kevin were also there for the event.

The party began Saturday evening, at the Wynn Las Vegas. Nick and his brothers attended a meet and greet with the cast of ‘La Reve – The Dream”. His girlfriend joined them afterwards, along with other family, for a dinner at Andrea’s. They ate many different types of sushi and even received chopsticks with their names engraved on them, according to E! News.

The Las Vegas Sun reported that on Sunday, Nick had a relaxing day while playing golf with his brothers and watched football before dinner with friends and family at the steakhouse at Encore.

“At exactly midnight, Nick was watching his iPhone’s date change over to officially ring in his birthday. The group erupted in applause as a birthday cake was presented by the staff. The brothers sang “Happy Birthday” and Culpo snapped pictures of her man on her phone for social media. The couple cozied up for a cheers with a celebratory glass of champagne followed by a sweet kiss. Fifteen minutes after turning 21, Nick led the group to the red carpet at XS nightclub, where the brothers all snuggled up to their significant others,” according to E! News.

[Image via Youtube]