Rihanna Celebrating Her Birthday At Les Deux

The Umbrella singer - Rihanna who doesn't turn 20 until Wednesday - was partying with friends including Kanye West and actor Wilmer Valderrama at Los Angeles' Les Deux nightclub when the food fight began on Tuesday night.An onlooker said: "There was cupcake frosting all over Rihanna's face and the group was hysterically laughing to the point of almost tears!"Chris Brown, who is rumoured to be