In the one-minute clip, Swift is seen playing the beginning of her new song - 'We Are Never Ever Getting Back Together' - before Kevin Hart barges in on her.
'Really? Taylor, for the last time stop writing songs about me," says Hart, who is hosting the ceremony.
Swift responds: "This isn't about you at all."
Swift is set to perform 'We Are Never Ever Getting Back Together' at the Video Music Awards, which will also feature Pink, Green Day, One Direction and Alicia Keys in the performance lineup.
The 2012 MTV Video Music Awards will air on Thursday, September 6 at 8/7c.