Russ Einhorn / Splash News 1 / 7
Russ Einhorn / Splash News 1 / 7

Kristen Stewart was left covered in bruises after struggling with her pole-dancing routine in upcoming film "Welcome To The Rileys."

The actress plays a 16-year-old exotic dancer in the drama, and admits she was not prepared for the physically grueling stripping scenes.

She tells E! Online, "I did some pole dancing. I got bruises all over my legs. I tore myself up doing it. It sucked. (But) the more I saw it, the more I wanted it (to perform). It was like a weird self-hating kind of thing. The cool thing about my character is she is not sultry and she is not sexy."

Director Jake Scott asked the "Twilight" beauty to take lessons from a real stripper, but insists Stewart was still scared of shedding her clothes even though the set was closed off to everyone but cast and crew.

He adds, "She was terrified. The strip club we shot in was really a club, and it really was that dirty and really that tough. But she killed it."