01/15/2011 09:31 am ET Updated May 25, 2011

Emmy Rossum Talks Sex Scenes And 'Shameless'

Having spent her whole career virginally pent up in period piece costume, Emmy Rossum, once star of 'Phantom of the Opera,' and now star of the new Showtime series 'Shameless,' is excited to get rough and sexy -- especially sexy.

Rossum, who plays Fiona, the sexy yet mother-like eldest sister to a large, working class-at-best family, told Vegas Magazine that her love scenes with co-star Justin Chatwin are one of the best parts of the show.

"It doesn't make sense that the character would wear a bra and care at all about what she looks like when she's having sex," Rossum told the magazine. "Sex is meant to feel good, and she wants to feel good. Her life is so shitty in so many ways. Some people use alcohol, some people use gambling--and some people use sex."

Rossum also likes it, though, when the clothes stay on.

"We pretty much get no hair or makeup at all," she said. "They frizz out my hair a little and rub mascara around my eyes, and that's it. I love the no-vanity aspect of it. It's really liberating from having had so many years of period costume drama."

In a recent Esquire feature, Rossum showed off that new raunchy side, by wearing some revealing lingerie and telling dirty jokes.

For much more, click over to Vegas Magazine.