Remember Icona Pop's number one track I Love It and how incredibly couldn't-get-it-outta-our-heads catchy it was? Well, that was all Charli XCX – and now it's come out that the singer/songwriter is writing for Britney Spears' upcoming eighth album. According to a mystery countdown on Brit's official website, something's brewing and will be revealed in 21 days. Can't. Take. The. Suspense.