Katherine Heigl isn’t proud of some her habits.

In an interview with InStyle magazine, the “Grey’s Anatomy” actress and star of the upcoming movie “The Ugly Truth,” says she is “ashamed” of herself for continuing to smoke, adding that “it’s so stupid.”

But one thing Heigl, 30, doesn’t feel any shame for his expressing her opinions – even when it gives her a bad reputation.

"I've got this moniker that I'm the foot-in-mouth gal, and I keep thinking, 'In what way?'” she said. “Because I said something you don't agree with? Because I said something you don't like? I'm just telling you my opinion. I hate the idea that I can't be honest about how I feel about things because it's going to piss somebody off who feels differently. That seems preposterous to me."

PHOTOS: Click here to see photos of Katherine Heigl, including exclusive InStyle shots.

But the criticism has hardly stalled her career momentum, as her new film with Gerard Butler might just be the box office's next big hit. Heigl says that part of that has to do with the frank subject matter of the film.

"I know this is going to sound bad but I'm really glad ['Ugly Truth' is rated] R. I didn't want to do another PG-13 movie. [In any real-life contentious relationship with romantic underpinnings] you're probably going to drop the F-bomb once in a while. You're probably going to say some things that are kind of harsh. And you're definitely going to talk about sex. It doesn't have to be so Snow White and Prince Charming."

Click here to read more of Katherine Heigl's interview with InStyle

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