Just when you thought you knew everything there was to know about Taylor Swift and Calvin Harris' breakup, out come reports that Taylor Swift actually wrote Harris' hit "This Is What You Came For" and that his failure to acknowledge or give her credit in any way is what really caused their split.

No, they are most likely never, ever getting back together.

The story, according to TMZ, allegedly goes like this: Swift wrote the song on piano and sent it from her iPhone to Harris, who was super into it. They went into the studio and recorded a demo of it, with Harris doing the beat (he's a DJ, after all) and Swift on vocals.

They knew they had a hit on their hands, but Swift had written it for Harris, so they decided to keep her involvement a secret, for fear that the backstory might detract focus from the actual song. So Swift kept the publishing rights, but used the pseudonym Nils Sjoberg on the credits.

Harris released the track on April 29, with Rihanna (with whom he'd done "Now That We Found Love" five-years-ago) on vocals, and it immediately became a huge hit.