Katy Perry RobynInsulting Katy Perry doesn't seem like a very nice thing to do, especially if she is the headliner of the tour you are on, but that is exactly whatSwedish pop star, Robyn has done.

Robyn -- who you may best remember for her 1997 mainstream hit 'Show Me Love' and who has since reinvented her self as an edgier, out-of-pocket pop singer -- made a catty comment about Perry in an interview with Time Out.

When questioned about her plans to open for Perry's California Dreams tour Robyn explained, "I was asked by her to do it and thought it was a good way of getting to know her audience. It's bigger than mine [laughs]." In response to the follow-up question, "And are you a fan of hers?" Robyn responded, giggling, "You know what? I have to go now."

Robyn's jab at Katy ignited rumors that the tour mates were trapped in a heated rivalry and prompted Robyn to make a follow-up statement in an interview with MTV.