Rob Kardashian and Rihanna
Courtesy of Pink + Dolphin
08/28/2012 at 06:00 AM EDT
Where do broken hearts go? To the club!
spent Saturday night at Hollywood nightclub Playhouse, where the singer and other stars were on hand to celebrate the launch of Pink + Dolphin's flagship store.
During the evening, the "Where Have You Been" singer was stationed at her own VIP table across from ex-boyfriend Chris Brown
. Brown sat with Christina Milian
and Sean Kingston
as Chief Keef performed.
Although Rihanna, who recently told Oprah she "still loves" Brown
, was surrounded by friends, her mind seemed to be elsewhere. The 24-year-old slowly sipped drinks, while "pretending to dance and mingle," but kept her eyes on "all the fun Chris and Christina were having," a source tells PEOPLE.
later took a seat at Rihanna's table where he got a little flirty with her and shared a few laughs, says a source. But, "you could tell she really just wanted Chris to pay attention and talk to her, but he was totally ignoring her," the source adds.
– Jen Garcia