Swift confirms Styles inspired 'I Knew You Were Trouble'

Taylor Swift has confirmed 'I Knew You Were Trouble' was written about her ex--boyfriend Harry Styles.

The 23-year-old pop star gave a scintillating rendition of the song at the ceremony in February as the One Direction heartthrob looked on, and she found it easy to connect with her emotions as the person she wrote it about was so close to her.