Katy Perry

Katy Perry has never been shy about admitting that she had a crush on a female friend at 15. Hello! That's what allegedly inspired her first smash hit 'I Kissed a Girl.' However, Perry never revealed to her friend that she was crushin'. Actually, it was more than crushin'. It was her first love.

Even though Katy Perry's first marriage ended in divorce after only 14 months, the singer's relationship with reformed Lothario John Mayer is going so well (despite that hiccup this past spring), that sources say it's pretty certain that they will get engaged.

So much for letting the light in! Katy Perry's chart-topping album 'Prism' has been labeled a biohazard in Australia.

Get your Kleenex ready. A terminally ill teenage girl sang 'Roar' by Katy Perry, it went viral, and, well, yeah. It's heartbreaking and inspiring at the same time. 16-year-old Olivia Wise, suffering from an inoperable brain tumor, belted out the tune, and her loved ones made her Internet famous for it.

Katy Perry and Niall Horan are engaged ... but in an Instagram photo only!

When Katy Perry hit an L.A. karaoke stage with pal Robert Pattinson in 2008, little did she know she'd be talking about it now.

File this one under "Mick Being Mick," "Of Course He Did" or just "Ewww."

Congrats to Katy Perry, as her new album 'Prism' debuted at No. 1 on the Billboard Top 200.

Another day, another cover for Katy Perry. The singer covers the December issue of Glamour U.K., with a feather in her cap, er, hair. The singer also flashed her dazzling smile and discussed her divorce from Russell Brand in the accompanying feature.

Katy Perry and Robert Pattinson are pals, so close that they fart around one another without embarrassment. The twosome once sang some (presumably) drunken karaoke back in 2008, too.