Kim K and Rihanna stun at RiRi's charity event

Kim K looked beautiful in a plunging sheer sequin gown, which she wore over a revealing bodice as she attended Rihanna's first-ever Annual Diamond Ball held in honour of the Clara Lionel Foundation at The Vineyard in Beverly Hills last night. Rihanna looked even more stunning in a rose satin gown. See more pics from the charity event after the cut...

 Rihanna with her brothers, mother, aunt and grandfather

Then she changed to this beautiful dress to perform...