Katy Perry's ongoing feud with Taylor Swift is almost as legendary as Kanye West's. The difference has been that while Kanye (and Kim Kardashian, and Calvin Harris...) has taken his beef public, Katy has played fairly coy about the bad blood brewing between her and the 1989 pop star.

On Saturday (September 10), the "Rise" singer addressed the contempt between her and Taylor publicly and overtly for what seems to be the first time (notwithstanding any previous subtweets or cryptic, covert shade) on Twitter, implying that she is owed an apology by the other artist.

When asked by a Twitter user if she will ever "collab with Taylor Swift," Katy swiftly responded, "If she says sorry, sure!"

Back in January 2015, Katy subtly touched upon her rumored feud with Taylor during a pre-Super Bowl Halftime Show interview with Billboard, saying, "If somebody is trying to defame my character, you’re going to hear about it."

Months earlier, in September 2014, the pop star tweeted, "Watch out for the Regina George in sheep's clothing...," which many took to be about her beef with the "Bad Blood" singer.

However, it wasn't all tea-spilling for the prismatic pop star on Twitter: When a fan brought up the single war that took place between Katy's "Roar" and Lady Gaga's "Applause" when both lead tracks debuted back in August 2013, she revealed, "I hated those days."

When asked by another user if they should go to the club or spend their night on Twitter, Katy, apparently a Little Monster herself, put her paws up and responded, "#BuyPerfectIllusionOniTunes"

Fifty Shades of Celebrity Feuds:

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