Katy Perry would work with Taylor Swift only if she apologize

While answering random questions of her fans on Twitter, superstar singer Katy Perry said she would collaborate with Taylor swift if she says a sorry.

"@HerWonkEye @katycatsophia @camilasviews if she says sorry, sure!" Perry responded when one of her fans quizzed about the two working together, reports E!Online.

The two pop stars have been in a prolonged tiff that is yet not settled. It started when the 'Love Story' songstress claimed in an interview that Perry tried to steal her tour's dancers out from under her.

Swift later tweeted to fans, "Watch out for the Regina George in sheep's clothing."

Since then, things are not very well between the two, it further escalated after swift broke up with her former beau Calvin Harris.

After she took credit for co-writing his hit song with Rihanna, Harris took to twitter to slam her and brought up Perry in the process.

"This Is What You Came for," he tweeted.

"I figure if you're happy in your new relationship you should focus on that instead of trying to tear your ex bf down for something to do. know you're off tour and you need someone new to try and bury like Katy [Perry] ETC but I'm not that guy, sorry. I won't allow it," he further wrote.