Talk about misspent youth! 7th Heaven starlet Jessica Biel, 19, still feels haunted by her scantily clad appearance on the cover of Gear magazine last year. "It was really, really a bad decision on my part," she tells TV Guide Online. At the time, her provocative posing may have made the youngster appear all grown-up, but it also tarnished her relationship with her family, fans and Heaven boss Aaron Spelling.

"I got involved with the wrong people," says a newly blonde Biel, who plays a girl pitching woo to Freddie Prinze Jr. in Summer Catch (opening Friday). "I won't say they took advantage of me — because I absolutely participated in it — but I made a really bad choice."

Biel says she wrong-headedly chose to pose out of anger toward someone, whom she opts not to identify. As she recalls: "I was just being a little brat, going through a really tough time in my personal life. It was such a huge learning thing, and it's too bad I had to learn it in front of everybody. I know it was a blessing in disguise from up above. He was telling me, 'You're going to learn this now so you don't do it later.' But if I could take it back, I would take it back for sure."

The actress/college coed — who's taken a year off from Tufts University to work on Heaven full-time — now feels she has a moral responsibility to her young audience. "I do feel an obligation to be a role model," Biel says, "because there really aren't that many girls on TV that your parents can go, 'This is a really cool person. Look how she lives her life. Look how she handles this.' It's scary to think that I might have hurt a girl [in] some way by saying something or wearing something [inappropriate]."