VIDEO: Selena Gomez dances to Taylor Swift's 'I Knew You Were Trouble'

Selena Gomez's favorite song is Taylor Swift's 'I Knew You Were Trouble', which has been rumored to be about her alleged new boyfriend, Harry Styles.

On the eve of the official video's release, which is later today, Gomez posted this video on YouTube of 'her and her girls' dancing to the song following a choreography by Gweny.

"Me and my friends just goofing around to our favorite song :) I want to give a big thanks to my friend Gweny for Choreographing this fun dance. My girls for being amazing and for Taylor being such an inspiration. Thanks Dan for the awesome edit! Hope you enjoy!" Gomez wrote.

Then she posted a link to it on Twitter, which was re-tweeted by Swift herself.

Today, December 13th, is Swifts 23rd birthday and the day of the premiere of her 23rd video, or so she said.