What are celebrity best friends for? To promote your latest single of course!

Selena Gomez made another home video – this time to Taylor Swift’s "I Knew You Were Trouble" … not that the Grammy winner needs any help selling records.

But hey, the video did go viral! We’re guessing it’s because Selena and friends Samantha Droke, Francia Raisa and Laura Quinn do a pretty sexy dance routine to Taylor’s tune!

Gomez shared the video with her 13 million Twitter fans on Wednesday posting, “SO Cheesy, I know but I’m glad I’ve got my girls …and Gweny … : ) @taylorswift13 we love you!!!”

Of course T-swift replied to her bestie writing, “@selenagomez I love you so.”

How cute are they? Check out Selena’s sexy dance moves in the video above!