Taylor Swift and Zayn Malik just surprised everyone.
The duo revealed on social media late Thursday that they had collaborated on a song called "I Don't Wanna Live Forever," for the upcoming Fifty Shades Darker soundtrack.
Shortly after the song was released on iTunes it went to No. 1 and Swift couldn't help but acknowledge how quickly they hit the top spot.
"Well that escalated quickly. @jackantonoff @zayn @sam_dew," Swift posted on Instagram with a photo of their song in the No. 1 slot.
Taylor actually wrote the song with Jack Antonoff, the boyfriend of her BFF Lena Dunham, and singer-songwriter Sam Dew.
Jack explained how the song came together on Twitter, "I don't wanna live forever came together very quickly. wrote it with taylor and sam dew and produced it at home mostly on paper sounds."
He continued, "Recorded taylor at my house. zayn sent parts from LA - we did it in a week basically. i've never had something come out that quick."
Take a look at the E! News video above to get more scoop on T.Swift and Zayn's collaboration!