Actress Jessica Alba says she may have played sexy characters on-screen but she never slept her way through Hollywood.

The 33-year-old may have caught the attention of many when she played stripper Nancy Callahan in "Sin City", a role she will reprise for the movie's sequel titled "A Dame to Kill For" later this year.

Alba said her on-screen sexiness is all an act, reports contactmusic.com.

"I never slept my way through Hollywood, so I never felt like I compromised. Apparently, people do it, I didn't. I felt like I never compromised myself because I'm a prude," said Alba.

"I don't know. I grew up Catholic. In my head, I'm always thinking - 'Oh God, can my grandma see this," added the mother of two.

The actress started her film career aged 13 before getting her big break appearing on the remake of TV series "Flipper" (1995).

She has daughters - Honor, five, and Haven, two - with husband and actor Cash Warren.