Taylor Swift has used her only concert for 2016 to remind everyone just who wrote Calvin Harris & Rihanna‘s hit track ‘This Is What You Came For‘ – Taylor.

She performed a piano rendition of her ex’s hit song at the Formula 1 United States Grand Prix on Sunday, marking it as the only departure in a setlist that was otherwise filled with her hits from the last decade.

As is now preserved forever in the annuls of pop culture history, TIWYCF found itself in a bizarre custody battle in July this year, shortly after Taylor and Calvin broke up and even more shortly after #Hiddleswift was born.

Taylor’s people leaked to gossip mags that she wrote the damn song, actually, and Calvin accused her on Twitter of stirring up drama to deflect from bad press about her moving on to dating Tom Hiddleston.

According to Calvin, Taylor wrote the lyrics but wished to remain anonymous (she was initially credit with the pseudonym Nils Sjöberg), agreeing with him that releasing a song together would have overshadowed the song itself. He claimed to have written the music, produced the song and arranged it.

Essentially, Taylor performing her ex-boyfriend’s song – despite the fact that she wrote the lyrics – is just so damn petty, and we are 100% here for it.

Before she performed the song, T-Swift said:

“As a songwriter, the most rewarding feeling in the world is writing something and then having a crowd sing it back to you because they know the words, it’s the coolest thing in the world. And um, I’ve never played this song live before, but you know it. Maybe you can sing along and then I’ll get to know what that feels like to hear that song back, can you?”

The fans are SHOOK:

The haters are shook.

Pretty much everyone is shook, because let’s face it – everyone is here for drama.  

Keeping one eye on Calvin’s Twitter account, tbh. No salty tweets yet, but more as and when.

Photo: Twitter / @The1989Tour.