Rihanna and Chris Brown have broken up.

A source tells E! News that RiRi is choosing to focus on her career and business ventures for now, and was spotted smoking weed at Greystone Manor in Los Angeles last night.

Meanwhile, the 'mystery blonde' that Chris Brown was spotted with over the weekend has been identified as Keisha Kimball, a 22-year-old waitress at L.A.'s Playhouse nightclub.

She denies that anything is going on with Breezy.

"I am always Chris' waitress," she tells TMZ. "I know him and I am friends with his friends. Nothing has ever happened. I just work there... I don't go for black guys."

Just last week, Chris Brown appeared on The Today Show and sung the praises of his renewed relationship with his embattled girlfriend.

"Everything's good," he told Matt Lauer. "We're fine."

As Jay-Z might say, it was all good just a week ago.

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