Katy, Britney And Ke$ha's Secret Link? Bonnie McKee Reveals!

McKee tells MTV News a few stories behind such smashes as 'California Gurls' and 'Hold It Against Me.'

On any given day on the radio, you'll probably hear one of Bonnie McKee's many sun-kissed pop smashes. Long before dropping her 2013 single "American Girl," the pop up-and-comer was already co-writing hits for the likes of Britney Spears, Katy Perry and Ke$ha, among others.

While McKee's latest co-writing credits include Spears' "Ooh La La" and Perry's "Roar," she also co-wrote "California Gurls," "Hold It Against Me" and Ke$ha's "C'Mon." When McKee recently stopped by MTV News, she broke down the story behind all three of those inescapable hits.

So Hot We'll Melt Your What?

Perry's longtime pal knew that the magic of Perry's 2010 Teenage Dream hit, "California Gurls," could be found in a double entendre.

" 'California Gurls' actually started with one line. It felt really summery," she explained. "We had the melody and we had a track and we knew we wanted to do like a summer banger. And so the first line that I wrote, I said, 'We should say something about a popsicle, about melting a popsicle.' And then it was like 'Popsicles, where does that go?'" The short answer: to the top of the charts.

Katy's 'Hold It Against Me' Connection

Perry and McKee may have secretly slipped some secret background vocals on "Ooh La La," but long before that, Perry served as the muse for Spears' 2011 Femme Fatale single, "Hold It Against Me."

" 'Hold It Against Me' was actually inspired by Katy Perry," McKee said. "I was in the studio working on Teenage Dream and that whole album with Katy and I was simultaneously working on Britney stuff. I had started this song and I hadn't really gotten the hook yet."

That is, until her real-life teenage dream walked into the studio. She continued, "And Katy came in in like a skintight, little sexy dress. And I was like, 'Damn, Katy, if I said you had a nice body would you hold it against me?' And I was like, 'Ding, ding, ding'."

Ke$ha's Got 'Flow'

In 2012, Ke$ha declared herself a Warrior and invited McKee to her pop music battle. The twosome worked together on the flirty "C'Mon," which McKee said was "really fun" to write.

"Ke$ha is a blast and she's so, so talented. I love her voice. I love her flow. When I came in, they had already kind of started it," she said. "And then we kind of started getting into the visuals and the verses. And again we were at the Maxi Mart, I think, at the corner [when it happened]. And I was really proud of the saber-toothed tiger line and 'sipping on a warm Budweiser' and all that. So it was a really fun song to write with her."