Selena Gomez knows how to make a song go viral -- not that Taylor Swift's "I Knew You Were Trouble" needs any help.
Last year, Gomez -- along with ex-boyfriend Justin Bieber and a few of their famous friends -- gave "Call Me Maybe" the boost it needed to become a mega-hit with their homemade music video, and now she's done the same for Swift's tune.
Swift's 20-year-old BFF posted a video of herself and pals Samantha Droke, Francia Raisa and Laura Quinn doing a very sexy dance routine -- and it's something we'd expect more from another former Disney star.
Gomez posted the video on Twitter on Dec. 12, and wrote:
"SO Cheesy, I know but I'm glad I've got my girls..... and Gweny... :) @tayorswift13 we love you!!!"
Swift seemed to appreciate the video, as she tweeted back at Gomez:
"@selenagomez I love you so."