As Taylor Swift celebrated her 23rd birthday yesterday with some quality time (and cupcakes!) thanks to One Direction's Harry Styles, the pop star gave fans a gift from her as she debuted the video for her latest single, I Knew You Were Trouble!

In the video, Swift showed off an edgier side as she crooned about falling for the wrong guy, played by Broadway actor Reeve Carney. Wonder which ex she's referring to?

Watch Taylor tell her side in song form in the video above!