Chris Brown was holding a launch party for the Qubeey Channel - which is Brown's new customised online channel intended to allow his fans to gain exclusive access to his life.
A source told HollywoodLife.com that Rihanna decided to take some time out from recording her new album, Unapologetic, in order to visit the launch party at the Playhouse nightclub.
The insider said: "I know it's a lot easier for her to concentrate and work hard now that Chris is back in her life.
"She don't worry about the bullshit no more. She don't wonder about what he's doing or who he's with. It's like she feels more secure and confident when he's in her life."
The pair are still not officially together, but were apparently 'hugging and kissing' at the event as well as sharing drinks and a cigarette.
Chris Brown at the launch of the Qubeey Channel at Playhouse, Beverly Hills.
This follows news that Brown recently broke up with his girlfriend Karrueche Tran because of his friendship with Rihanna.
Brown stated: "I have decided to be single to focus on my career. I love Karrueche very much but I don't want to see her hurt over my friendship with Rihanna."
He then added, "I'd rather be single allowing us to both be happy in our lives."
Watch Rihanna's lyric video for new single 'Diamonds' below:
Below: The many men of Rihanna - her dating checklist