According to one website's source, the song was written about Harry.
We don't believe it though!
HollywoodLife.com reports that they have the exclusive scoop on Taylor's "IKYWT," with a source noting, "The song 'Trouble' is definitely about Harry. Taylor told Harry it's about him. She references flying around America following One Direction's tour in the song."
We think the source may be a little off base, since "I Knew You Were Trouble" was written before Taylor knew Harry.
She recently told MTV.com the details behind "I Knew You Were Trouble," sharing, "I had just gone through an experience that made me write this song about like knowing the second you see someone, 'Oh this is going to be interesting. It's going to be dangerous, but look at me going in there anyway.'"
Taylor added, "I think that for me, it was the first time I ever kind of noticed that in myself. When you are curious about something you know might be bad for you but you know that you are going to go for it anyway because, if you don't, you'll have greater regrets about not seeing where that would go."
Do you think "I Knew You Were Trouble" is about Harry?
WATCH: Harry and Taylor's New Year's Eve Kiss Video!