Katy Perry wanted her appearance in Taylor Swift's music video to be a "symbol of redemption and forgiveness"

Taylor said: "When I thought of this concept for the video and I wrote the treatment, I thought, 'I'm just gonna ask her if she'd be interested in this, but I would be totally fine if she'd rather keep it private.' But I sent her a long synopsis of the entire video and she was like, 'I would love for us to be a symbol of redemption and forgiveness!' "

Earlier this year, Katy wore a hamburger costume to a Met Gala afterparty and Taylor admitted that inspired her to incorporate the outfits into the video as she thought they were the perfect "metaphor" for their relationship.

Speaking on the BBC Radio 1 Breakfast Show, she said: "I didn't think of the burger and fries costume until she wore the burger to the Met Gala after party and I was like, 'That is amazing.'

"I kept thinking...we are gonna have this moment in the video...and if it's us wearing normal clothes and hugging, it won't really fit...So I was like, 'Can we do a a burger and fries as metaphor for two people who belong together? And people who are a perfect pair?' And she thought it was really funny! So we did it."

The two pop superstars were believed to have fallen out after Katy took three of Taylor's backing dancers for her 'California Dreams' world tour before her 'Red Tour' had finished in 2013.

The pair then traded verbal blows on Taylor's track 'Bad Blood' and Katy's song 'Swish Swish' before the 'Firework' hitmaker sent an actual olive branch as a peace offering during her rival's 'Reputation' tour last year.