She was credited as Nils Sjoberg, keeping it schtum until now, for some reason - her people have confirmed the co-write to People.
It's unclear exactly what bit she appears on - harmonies perhaps? - but she's in the mix somewhere. It's probably not exactly what people wanted when they asked for a Taylor x Calvin song, or even a Taylor x Rihanna song (did people ask for that?), but oh well, it's technically here nonetheless.
Ex-beau Harris took to Twitter to confirm the news, calling her an "amazing lyric writer" before stoking the Twitter beef/calling her out.
I wrote the music, produced the song, arranged it and cut the vocals though. And initially she wanted it kept secret, hence the pseudonym
— Calvin Harris (@CalvinHarris) July 13, 2016
And she sings on a little bit of it too ��
— Calvin Harris (@CalvinHarris) July 13, 2016
Amazing lyric writer and she smashed it as usual https://t.co/vW3yGOIJit