Chris Brown's ex-GF ,Karrueche is dating rapper Kendrick Lamar. At last night's Kendrick Lamar concert at the Roseland Ballroom in NYC, Kae was backstage with Kendrick's people. Officially she was working as Kendrick's "stylist" . . . but he was really there as his personal guest. We're told that he two just started dating, so it's nothing too serious. But that both parties are very interested in seeing where things go from here. Oh and did we mention that Kendrick and Chris are FRIENDS!!!! Wonder how Chris is gonna take the news of his sideline chick dating someone who right now is hotter in the game than him.