Rihanna and Brown in 'don't sit with me' tiff

Rihanna "refused" to sit with Chris Brown during a night out on Wednesday.

The on/off couple have sparked speculation they have ended their romance again after the 'Stay' hitmaker refused to be seated near her 'Don't Wake Me Up' singer beau at Popular Demand's one-year anniversary party at the Playhouse night club in Los Angeles, and the pair ignored each other all night.