New Rihanna Song Features ... Chris Brown

Looks like Rihanna and Chris Brown are more than making up. Almost three years after Brown pleaded guilty to assaulting his ex, the two are collaborating on an upcoming single, MissInfo reports. The producers of "Birthday Cake (Remix)" had earlier said that the song's featured artist was "gonna shock the world." Indeed. Brown reportedly raps on one verse and sings on a second, though it's unclear if that's what will be in the final cut; the single is due out next week. Meanwhile, Brown reportedly came to Rihanna's birthday party following the Grammy Awards (click to see her risque cake); the two have also been clubbing together, Vibe notes. (In other Chris Brown news, he's reportedly been using a really tasteless pick-up line...)