Katy Perry says she'll collaborate with Taylor Swift 'if she says sorry'

After two years of bad blood, could we be seeing the first stages of a détente pop music's most notorious feud? Just months after Calvin Harris took Katy Perry and Taylor Swift's falling out to new levels of awkward with a very public Twitter rant at his 'Shake It Off'-singing ex, Perry has admitted that she'd be willing to collaborate on music with her former friend. The only condition? She wants Swift to apologise to her. Perry made the unexpectedly candid comment during a Twitter Q&A with fans over the weekend, responding to one use who asked: "Will you collaborate with Taylor Swift[?]" Instead of ignoring the loaded message, Perry issued a surprising reply. "If she says sorry, sure!" the 31-year-old wrote. katy-taylor Whether Taylor plans to take Katy up on the offer, however, remains to be seen. The pair's falling out went public back in late 2014 after Swift revealed that her diss track 'Bad Blood' was about a fellow female pop star who had "tried to sabotage" her arena tour. The incident led to Katy labelling Swift a "Regina George in sheep's clothing" - a reference to the bitchy Queen Bee of 2004 teen comedy Mean Girls - and also tweeting a cryptic message describing time as the "ultimate truth teller"; a message she pointedly retweeted after Calvin Harris accused Swift of trying to "bury" him "like Katy" back in July. Who knows, perhaps if Swift can bury the hatchet with Kanye West as well as Katy, the trio can create a super-group of formerly feuding pop stars. Until then, we suppose we'll just have to make do with them solo... More stories: Colton Haynes can’t stop sending nude photos to his friends Nyle DiMarco discusses sexuality and changing deaf lives in Attitude’s October issue