Rihanna spent Sunday on the set of her new music video, "Diamonds," for which she donned a sexy see-through gown. But we have a feeling RiRi had something else on her mind during the shoot–namely her controversial ex, Chris Brown, with whom she was spotted Saturday night. Rihanna and Brown were caught on camera canoodling at a launch party for his Qubeey website at Playhouse nightclub in Beverly Hills.