Carrie Underwood cries on planes.

The 'Before He Cheats' singer gets very emotional when she takes to the skies and often finds herself getting teary eyed at the slightest of things.

She said: ''I seem to cry a lot on planes when I watch movies. I think it has something to do with the pressure and the funky air. I watched the latest 'Twilight' and I'll admit that I got a little misty.''

However, Carrie doesn't get embarrassed by her crying as it takes a lot for her to be left red-faced.

She told The Sun newspaper: ''I don't get embarrassed easily. But I was on stage once in Yakima, Washington, and I said Yamaha instead of Yakima. That's the only time I ever messed up. But they laughed, they were with me.

''I got booed for saying I was a vegetarian in Nebraska. It's a big livestock area, I'm still not sure how it came up.''

The 2005 'American Idol' winner also revealed how she secretly wore braces on her teeth last year and was pleased nobody found out.

She said: ''I wore braces at the beginning of last year for three months and no one knew.''