I Knew You Were Trouble (Red)

Hidden Message: When You Saw Me Dancing

One of Taylor's favorites off her latest album Red, the track I Knew You Were Trouble features Swift's first ever dubstep inspired breakdown. There has been a lot of speculation over which of Swift's ex's is the subject of the latest breakup anthem but the majority seem to have settled on John Mayer. The lyrics  do seem to allude to those of Swift's other song about Mayer, Dear John. (And I'll look back and regret how I ignored when they said run as fast as you can.) Swift explained the song is about "kind of being frustrated with yourself because you have your heart broken and you knew when you first saw that person you saw all these red flags and you just went for it anyway." Sounds a lot like her controversial relationship with Mayer. The lyrics,  A new notch in your belt is all I'll ever be/ And now I see, now I see, now I see/ He was long gone when he met me/ And I realize the joke is on me, also seem to allude to the musician who has a notorious playboy rep. 

* We also consider Joe Jonas a potential subject due to the opening line, Once upon a time, a phrase which Swift also used in Forever and Always. She also states that the perpetrator was "a few mistakes ago" which could open up the time frame to include a relationship even as far back as Joe.

Sources: 1, 2, 3, 4

John Mayer

Mid 2009 and Early 2010 (Dear John, The Story of Us, Superman, I Knew You Were Trouble)

Mayer tweeted about wanting to record a song with Swift in March 2009. The single Half of My Heart appeared on Mayer’s 2009 album Battle Studies. After the end of their twisted and secret relationship, Taylor wrote Dear John, which Mayer told Rolling Stone "really humiliated" him. In response, Taylor said it was presumptuous that he assumed the song had been meant for him. The Story of Us is about an encounter the two had at the 2010 CMA's. Superman was presumably written near the beginning of their relationship, and the lyric "I loved you from the very first day" is the hidden message for Dear John. Some would argue that Haunted is also about Mayer...but we may never know. The saga continues on Red with I Knew You Were Trouble - the tragic tale of Taylor's venture into "places she's never been" with the man she knew was trouble as soon as he walked in.Mayer has returned the favor penning at least two songs of his own about the relationship Paper Doll and Shadow Days.