Guess who Rihanna's collaborating with on her upcoming album, the appropriately-named Unapologetic? That's right, a certain ex-boyfriend who assaulted her: Chris Brown. Rihanna revealed the collaboration in a handwritten track list she tweeted yesterday, Us reports. The song title is pretty much what you'd expect: "Nobodies Business." The two previously collaborated on two songs earlier this year. Click to see how Brown is coming between Rihanna and BFF Katy Perry.