'It's not hard... when the person the song is directed at is standing by the side of the stage': Taylor Swift admits I Knew You Were Trouble IS about Harry Styles

Wrote song for her album Red after she first dated the One Direction singer in March 2012

Song had already been released a few weeks before she and Harry gave their ill-fated romance a second try



She is famous for writing songs about her menagerie of famous ex-boyfriends.



And it seems the subject of Taylor Swift's most recent failed relationship is no exception.

The 22-year-old singer has finally revealed her 2012 hit single I Knew You Were Trouble is about her ex-boyfriend Harry Styles.



Speaking about her spirited performance at the 2012 Brit Awards in front of Harry and his One Direction bandmates, the singer was asked how she felt performing the number while her ex was watching.



Revelation: Taylor Swift, pictured at this year's Brit Awards, has revealed she wrote her hit I Knew You Were Trouble about One Direction star Harry Styles

Taylor told The Sunday Times: 'Well, it’s not hard to access that emotion when the person the song is directed at is standing by the side of the stage watching.'

Speculation had been rife that Taylor had penned the song about the One Direction star when they first briefly dated in Spring 2012, and the star appeared to confirm the rumours were true in the interview with The Sunday Times magazine.



Speaking about her performance of the song at this year's Brit Awards where she stripped down to a sultry black outfit, she said: 'You’re balancing the analytical side of your brain which is telling you where to go and how to go there, with the other side of your brain, which is saying "Feel everything you’re singing, and show it on your face.



'"Feel everything exactly as you felt it when you wrote the song."'

Acrimonious: Taylor, pictured with Harry Styles at the beginning of December last year, broke up with the boyband heart-throb in the new year

The song contains the lyrics: 'I knew his world moved too fast and burned too bright. But I just thought, how can the devil be pulling you toward someone who looks so much like an angel when he smiles at you?

Trouble: The star's single hit the top five in the U.S. billboard chart

'And when I fell hard you took a step back, Without me, without me, without me.

The chorus continues: 'Cause I knew you were trouble when you walked in. So shame on me now. Flew me to places I'd never been. Til you put me down.'

Even more damning perhaps, goes the line: 'A new notch in your belt is all I'll ever be. And now I see, now I see, now I see.'

Harry remained cordial despite uncomfortable scenes at the February London award ceremony, where the former couple were said to have refused to make eye contact backstage.



And in an exclusive chat with the Mail Online : 'I thought her performance was really good, she looked great.'



After a brief fling in Spring 2012, Taylor was heartbroken when Harry was photographed kissing American model Emma Ostily in New Zealand in April.



However, the young couple gave their romance another try last November.

But just days into the new year, they split up after less than two months together following a bitter row on a Caribbean holiday.



On January 5, she quoted a line from I Knew You Were Trouble on her Twitter page: 'Til you put me down.'



The country singer is famous for her songs about her ex-boyfriends.



Back to December is supposed to be about Taylor Lautner, while Dear John is a scathing homily to John Mayer.