Rihanna joined forces with Jay-Z and Beyonce Knowles in London last night to launch her new album, Rated R, in front of her British fans. In a black cutout dress, Rihanna arrived at the bash and posed for photos before changing into something with a little less fabric to take the stage, where she was joined by Jay-Z. Rihanna then put on a bright orange number for the afterparty at Mahiki, where she blew out a celebratory cake with sparklers. Beyonce and Jay-Z were spotted leaving in the early hours of the morning, as they continue enjoying some downtime before she moves on for a show in Manchester tomorrow. Her new video with Lady Gaga for "Video Phone" also just debuted — check that out after the jump.
To see more of the trio and Beyonce's new video, just