So the Rihanna and Katy collaboration is not recorded yet but at least we finally have a confirmation from the BFFs. "Bad Gal Riri" and the "California Girl" unite their pop star forces to create "the best song ever."

Katy Perry and Rihanna are one of the cutest best friends in the music industry. Though Ri and Katy also have other celebrity friends, these two have one thing in common: they're both singing sensations. We have been waiting for material from these two for... like... ever.

Katy confirmed this: "We've actually been talking about it for years, so we can't let anyone down. We have to do the best song ever. Beyond that, I think we'll definitely get around to it and when it happens, you are going to know." So yes, that can be in ten more years.

But... at least we heard it from Katy herself and we now know that the girls have really talked about it already. For now we can guess what the song will sound like. Do you think it will be raunchy and hip-hopish, like Rihanna's "Pour it Up" and Katy's "Dark House?" Or will it be soulful, like "Stay" and "Unconditional?"  Guess Katy is right -- we have high expectations for this duet.

While Rihanna seems to be emerging herself in fashion shows and endorsements, she has also been doing some collaborations. No new music from the "Diamonds" star has emerged but we have seen her combine forces with Eminem again, and now with singer Shakira. Katy, whose most recent duet has been with her boyfriend John Mayer, also has been doing some teaming up.

Could this mean that the girls will find sometime to record a great song together? Hopefully it will be sooner than later but we understand you two gals are busy taking over the world and stuff. Not to mention the amount of pressure you are in with this one. If a song between Ri and Katy flops... we're going to remember it forever (evil stare).