los angeles (SS) - RIHANNA and Chris Brown aren’t a couple, she insists. The Umbrella hitmaker — who had recently reunited with the 23-year-old R&B star despite the fact he is still under supervised probation for beating her in 2009 — was asked during a recent interview if she is still dating the Turn Up the Music hitmaker. “No. Not together,” she said.Recent reports claimed Rihanna’s pal Katy Perry wasn’t happy about her relationship with Brown.“They’re barely talking and ever since the couple reunited, there has been tension between them,” a source said.“Katy has been spending a lot of time with pals Robert Pattinson and Kristen Stewart.“Katy fears Rihanna is making a huge mistake and doesn’t want to be part of it.”ss