Someone with a very keen eye (or should we say ear) at Buzzfeed has uncovered this gem from Taylor and Zayn Malik's duet, I Don't Wanna Live Forever.
As Swifties already know, Taylor's lucky number is 13. Her birthday is the 13th of December, she writes the number 13 on her hand before performing, she believes she will only win an award if she's seating in the 13th row, and every time she posts a song screenshot on her Instagram it is paused on :13 seconds.
So, in the collab there is a part where she sings over and over the line, "Until you come back home." Want to guess how many times she sings the line?
You got it, thirteen times!