Chris Brown spotted with Karrueche a day after hanging out with RiRi

On Sunday night, Chris Brown and Rihanna showed up together at the Qubeey social network launch party in Beverly Hills. (pictured left)

A day later, that's yesterday, Karrueche Tran's car was spotted parked outside Chris Brown's house all night, and later seen following him to the studio (pictured right). Hours later, Rihanna Tweets what you see below...

Sometimes I'm happy for her. Sometimes I'm extremely sad for her. :-(