Well, the dress has been found ... to be a fake!
The thief who took the gown says he took the dress from Lupita's room at The London after finding the door ajar.
[Image via WENN.]
Singing the track Fresh Off the Runway from her album Unapologetic, she donned a skimpy pink lace Adam Selman outfit with a Lynn Ban necklace and adorably pink Manolo Blahnik booties.
Then, for her hit song Diamonds, she changed into a long black Vivienne Westwood skirt and matching corset.
Surprisingly, RiRi didn't wear diamonds, instead opting for a vintage pearl Depuis sunglasses, a vintage Chanel pearl choker, one Ellagem pearl earring , and long black lace gloves by Cornelia James.
Rihanna's black booties showed off her thigh-high nylons peeking out of the long slit in her skirt were made by Gucci.
In fact, a little more was peeking out of her….
Princess RiRi wasn't quite so princess-y when she accidentally revealed a little too much underneath that long skirt of hers.
Check out what we're talking about (below) then take a look at even more pictures from her performance, including pics with VS model Doutzen Kroes!
[Image via Ivan Nikolov/WENN.]