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... 

Photo credit: Getty/Access Photo