While American pop stars commonly deny having sex in their teen years, One Direction are open books when it comes to their sex lives, admitting that they fear impregnating a girl.

In a new interview with OK Magazine, the guys kiss and tell, dishing on everything from their past and present relationships. When asked if they ever had a pregnancy scare with a girl, Harry Styles says, "The first time I had sex I was scared I got the girl pregnant -- that was despite the fact we were safe. Luckily we were fine."

Louis Tomlinson also admitted that he fears fatherhood at his age. "Even though I love kids, the thought of having a child now is pretty scary," he reveals. "It's one of my worst fears. I'm not against teenage pregnancies -- my mum had me at 19 -- but I'm not ready. My mum would kill me if I got a girl pregnant now."

We have a hunch Justin Bieber can relate.

One Direction are prepping for the release of their debut album, 'Up All Night,' which is set to arrive on Nov. 18. The guys recently returned to the 'X Factor' stage to perform their latest single, 'Gotta Be You,' before a live audience.