MUMBAI: What happened in Vegas isn't necessarily staying in Vegas.

Justin Bieber and Hailey Bieber went out for a fun night on the town on Saturday, July 10 with friend Kendall Jenner to celebrate her new tequila brand, 818 Tequila.

They hit up new club Delilah at the Wynn Las Vegas. The Biebers and Kendall were joined by friends Justine Skye, Ryan Good, Maeve Riley, Zak Bia, Kelia Moniz and other friends of the Biebs'.

"The group arrived together to Delilah after pre-gaming on a party bus that took them on the strip and then to the venue," a source connected to the club exclusively told E! News. "They arrived around 11:30 pm and were escorted to their own private table. The club was packed and many people were trying to approach their table."

The insider shared that Justin went on stage to perform some of his songs as a special surprise treat for the audience.

"He looked really happy to be singing and was dancing and vibing with the crowd," the source shared. "He was smiling and in a great mood. Several bottles of 818 tequila were brought out by club employees and everyone was chanting '818' and holding the bottles in the air. They were serving specialty cocktails with 818, including one that Kendall created, and had bottles on tables throughout the club."

In addition to Justin performing, he also poured shots for the crowd with Kendall, the source spilled.

The insider added that the group of women "definitely looked like they were having a fun girls' night out together and were all drinking and dancing together with the other girls at the table, while Bieber was on stage performing. They all left around 2 am."

The Delilah lounge is "inspired by the earliest showrooms and supper clubs of Las Vegas in the 1950s with a nod to both Parisian salon interiors and the epic set design from Hollywood's 'golden age,'" per the Wynn Las Vegas website.