Karrueche Tran and Chris Brown are nominally girlfriend and boyfriend, but rumors have been flying since his musical collaboration with Rihanna that the controversial couple are back together.
Karrueche, who describes herself on Twitter as "where Vietnam & the hood meet," and as half-Vietnamese, which is leading many to believe that Rihanna's recent tweet, accompanied by a photo of a bag of rice cakes dressed up in Karrueche's signature earrings and sunglasses, is a racist dig at Breezy's girlfriend. ("Rice cake" is a common epithet for those of Vietnamese descent, according urban gossip site Media Takeout.)
Gossip blogger Carlton Jordan also noted that the phrase is sung by Rihanna in the latest remix of "Cake" featuring Chris Brown: "Remember how you did it? / Remember how you fit it? / If you still wanna kiss it / Come and get it / Sweeter than a rice cake, cake worth sipping / Kill it, tip it."
Source 1, Source 2
According to Urban Dictionary, rice cake refer's to an Asian girl's vagina and be seen as derogatory