Katy Perry was having the time of her life on the 2017 MTV Video Music Awards stage until Taylor Swift decided to premiere the official music video of her single "Look What You Made Me Do" on Sunday. The release of the new song off her upcoming "Reputation" album came after the pop singer won her groping case against David Mueller earlier this month.

Swift drops new single ahead album launch

Taylor Swift even deleted the contents of her social media accounts as part of the preparation for her comeback since "1989" was released in 2014. The singer-songwriter uploaded a few teasers before she eventually confirmed November 10th as the release date of her sixth studio album.

Since she has not been actively promoting for several months, celebrities and fans alike were all eyes when Taylor Swift stole the spotlight at the 2017 MTV Video Music Awards with the release of her "Look What You Made Me Do" music video.

Perry reacts to 'Look What You Made Me Do' premiere

The "Speak Now" artist has obviously upstaged Katy Perry when she decided to premiere her new music video at the time when her enemy was hosting the awarding ceremony. A source revealed to E! News that the "Swish Swish" singer was not expecting Taylor Swift at the event.

It added that Katy Perry was in great spirits while preparing to host the 2017 MTV Video Music Awards. "This was her time to shine and really make an appearance for herself," the source said.

"She didn't want to let anyone down, so she kept a positive attitude."

When Taylor Swift's "Look What You Made Me Do" music video premiered, the "Roar" artist reportedly stayed backstage to prepare for her next appearance. "Everyone backstage was going insane over it, and a few people gave her the highlights," the insider added.

Another source told Hollywood Life that Katy Perry was "pretty upset" on how things turned out at the 2017 MTV Video Music Awards. She reportedly felt like that the spotlight was stolen from her by Taylor Swift who allegedly meant to hurt her nemesis with the premiere.

"In Katy [Perry's] eyes it just proves once again what she always felt — Taylor is the biggest mean girl in the business,” an affiliate said.

The bad blood between the two singers dated back to when three of Katy Perry's dancers decided to join her "Prism" concert series that required them to leave Taylor Swift's "The Red Tour" before its completion in 2014. Although she did not mention any names, the "Shake It Off" singer even accused a co-singer of trying to sabotage her concert tour by hiring some of her people.

Katy Perry, on the other hand, claimed that she tried to reach out to Taylor Swift in hopes to put an end to their misunderstanding.