Chris Brown is moving on from Rihanna quite quickly, weeks after announcing their breakup. He was seen after performing Sunday night at the Billboard Awards serenading his ex-girlfriend, Karrueche Tran.

The two were at an after-party in Las Vegas hosted by fellow artist Bruno Mars. “Brown was standing on the banquette dancing with Tran . . . he bent down a few times to kiss her, and kept running his hand through her hair and singing to her,” a source tells the New York Post’s Page Six.

The 24-year-old “Fine China” singer also spent his birthday with Tran this month at a Los Angeles, Calif., nightclub while Rihanna was in New York for her concert at Barclay’s Center.

Back in October, Brown broke up with Tran before getting back with Rihanna, and releasing a video, “The Real Chris Brown." The video shows private moments between him and Rihanna while the two are at a club, and cuts to him traveling with Tran. Brown admitting that he loves both women, saying, “I’m stressed out … when you share history with somebody, then you tend to fall in love with somebody else, it’s kinda difficult.

Is there such thing as loving two people? I don’t know if that’s possible, but for me, I feel like that,” while in the back of a taxi in New York. Brown and Tran had been together for close to two years at that point.

Now, it seems he has gone back to his former flame. While Brown was with Tran after the Billboard Awards, Rihanna was a no-show at the event, and later dined alone in Santa Monica.