Ethan Hawke left a "human sex book" in his daughter's room as he couldn't face discussing it with her.

The 43-year-old actor has daughter Maya, 15, with ex-wife Uma Thurman as well as son Levon, 12. He also has younger daughters Clementine, five, and Indiana, two, with wife Ryan.

Ethan is currently starring in Boyhood, a movie that was filmed over 12 years and tackles the issues of growing up. One topic covered is sex education, which Ethan admits he's struggled with teaching in real life.

“I’m an actor, I’m a bohemian person, but I still struggle, especially cross-gender,” he told British newspaper The Independent. “As parents, we don’t have a rule book about how to get the message across. I remember being completely petrified! I put a human sex book in my daughter’s room, I just left it in there – it had pictures and diagrams and stuff – just dropped it in there. It’s such a fine line of how to speak to a young person about sexuality.”

Ethan has spent nearly 30 years in the film industry, and has had his fair share of coming-of-age dramas.

His breakout role as pupil Todd Anderson in 1989's Dead Poets Society was one such role, and the actor concedes that for some reason it is much easier for men to make light of sex than women.

"I don’t know why it’s easier for young men to just make jokes about it, but the problem is that teenage pregnancy is extremely real, and a lot of young people don’t actually understand how their bodies work, or how a pregnancy will impact their whole life," he sighed.