(Cover) - EN Showbiz - Katy Perry has revealed that her crumbling marriage to Russell Brand took a serious toll on her while she travelled the world.

The singer is currently promoting her concert documentary Part of Me which followed her as she went on a challenging 124-date tour amid troubles in her now defunct union to the British comedian.

But the 27-year-old pop star says that everything got so on top of her at one point that she would literally be crying just before she hit the stage for her two-hour California Dreams show.

"There were times when what was going on in my personal life was so overwhelming that I had to bend over to let those tears fall straight out of my eyes and not my false lashes," she told the Hollywood Reporter. "Just as I'm about to go up on that ramp and sing Teenage Dream.

And she says that she will be giving a raw and revealing look into her life which is not always easy.

"Like how I write my songs, honesty has always worked for me," she said. "So if it ain't broke, why f**king fix it?"

And Katy says, like Kim Kardashian's ill-fated 72-day marriage to Kris Humprhies, "nobody knows what really happened except the two people who are in it."

Katy's divorce from Russell will be finalised next month. (C) Cover Media