Celebrity Justin Bieber Parties After His L.A. Concert with Kanye West, Kim Kardashian and Kourtney Kardashian The star celebrates the end of his L.A. shows with the reality stars By Melody Chiu Melody Chiu Instagram Twitter Melody Chiu is a Senior Editor for PEOPLE. She has been with the brand since 2009, editing, writing and reporting across all entertainment verticals. She oversees PEOPLE's music and events coverage and has written cover stories on Taylor Swift, Selena Gomez, Melissa McCarthy, Blake Shelton and Sandra Oh. The Los Angeles native graduated from the University of Southern California and has appeared on Extra!, The Talk, Access Hollywood and Good Morning America. People Editorial Guidelines Published on March 24, 2016 02:45 PM Share Tweet Pin Email Photo: Beretta/Sims/REX/Shutterstock After wrapping up the Los Angeles leg of his Purpose World Tour, Justin Bieber let loose with some famous friends – and a former flame. The singer was spotted partying at Warwick (co-owned by JT Torregiani and Sylvain Bitton) Wednesday night with Kanye West, Kim Kardashian and Kourtney Kardashian. 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.