Uh oh! Katy Perry started out innocently enough, discussing her as-yet-only-conceptual collaboration with Rihanna. But then she opened up a can of worms that we think she'll either backpedal from, retract or regret really soon -- she negged fellow divas Shakira (oh no!) and Beyonce (oh hell naw!).

In a recent U.K. radio interview, Katy opened her mouth and inserted her stiletto discussing the duet.

“We've collaborated on a lot of things, but just not songs yet," Perry said. "It's one of those things that's got so much build up that we have to deliver. I want it to be like that Eurythmics and Aretha Franklin song 'Sisters Are Doin' It for Themselves,' not 'Beautiful Liar,'" she said. Dang! Tell us how you really feel, Ms. Perry!

She elaborated on why it hasn't come together just yet. "But I definitely want to do something that is so iconic. [Rihanna's] kind of busy too. We're both busy but we planted the seed two years ago," she said. Then she got testy again. "How disappointed would you be if that song came out and it's no good? Sometimes you have to wait for greatness."

While we're sure the collaboration with RiRi is going to be pretty epic, if we were Katy Perry, we'd wait til our song was done before comparing it to one made by two living legends.

In any case, both Shakira and Beyonce are probably too mature and too busy with their own careers (and in Beyonce's case, Blue Ivy!) to respond. We just hope Katy's ready for the inevitable backlash. Instead of dissing the divas, she should probably learn a thing or two from them about keeping quiet to the press ... And maybe about moving her hips a little more gracefully.