Katy Perry 'sTwitter Row

Award winning pop artist Katy Perry and Calvin Harris appeared to engage in a public spat on Twitter, after the Scottish DJ allegedly pulled out of her Dublin and UK shows at the last minute. Katy Perry announced Harris would not be performing with her on Twitter,and she says: "FYI ALL UK & IRELAND SHOWS @CalvinHarris will NOT be joining in on the fun and has CANCELLED last minute." But Harris hit back, claiming Perry's "team" made it impossible for him to DJ. He tweeted: "Sorry to all who wanted to see me with Katy — her team suddenly moved the goalposts, and I was to appear on stage with no production." He sent another tweet just minutes later, saying: "Am really sorry @katyperry I'm just upset because I really wanted to play but ur team made it impossible." But the feisty Teenage Dream singer fired back: "@CalvinHarris… funny the goalpost seems to be perfectly fine for New Young Pony Club, Yelle, Robyn, Marina & The Diamonds, to name a few… it's fine, I'm used to you cancelling on me, it's become ur [sic] staple!" Perry kicked off her California Dreams tour at London's Hammersmith Apollo on 17 March, but due to an overwhelming demand for tickets, she has added two extra dates to her tour....