The group arrived around midnight “in great spirits,” says a source. “They sat at a VIP table near the DJ booth and were seen singing songs like Rihanna‘s ‘Work’ and his own song ‘Sorry.'”
Bieber – who canceled his tour meet-and-greets earlier this week – “was drinking and having a great time,” says the source. “He seemed like he didn’t have a care in the world.”
The Keeping Up with the Kardashians stars kept a low profile at the club. Kourtney, whom multiple sources confirmed to PEOPLE was hooking up with the pop star last year – sipped on drinks throughout the night.
“Justin and Kourtney were social, but you could tell they kept to themselves on purpose. There was no coziness,” says the source, who adds that Bieber left about 30 minutes after West and the Kardashian sisters, just before 2 a.m.