The hip-hop star attended the music ceremony as Katy Perry's date and the pair wore matching denim outfits as a parody of Britney Spears and Justin Timberlake's similar awards show ensemble in 2001.
Smith uploaded a picture to Instagram.com this week (begs25Aug14) showing him at the awards show with Perry and his pal Charli Xcx, but Riff Raff, who was seated next to the Roar hitmaker, is obviously cut from the snap.
He has blasted Smith for removing him, writing, "Thanks for cutting me out of the picture u chubby little f**k factory (sic). P.S. Your face is super huge @samsmithworld."
Smith has not replied to the comment.