However, last year it was reported that the beef was finally over, when Katy sent Taylor a literal olive branch in the post, and she has since made an appearance in her You Need To Calm Down video, where the two were seen sharing a hug and putting their differences aside once and for all (while dressed as a burger and fries, naturally).
Explaining how they came to be friends again, Taylor said on Monday’s Capital breakfast show: “She and I have really been on good terms for a while. She sent me a really nice note and an olive branch – like an actual olive branch – to my tour when it started. From that point on we’ve been on good terms.
“Then we saw each other at a party and walked up to each other and hugged it out and talked about things, and then we saw each other again and hung out at another party and it was just like something felt so much lighter about my life when things became really good between us.”
Taylor added that she didn’t want to go public with their renewed friendship until it was “solid”, a point they’ve finally reached, if their latest collaboration is anything to go by.
As well as her old-pal-turned-nemesis-turned-new-pal, Taylor also features a host of celebrity cameos in the You Need To Calm Down video, including the Queer Eye Fab Five, a host of stars from RuPaul’s Drag Race and Orange Is The New Black actress Laverne Cox.
Check out the full list of celebrity appearances here.