A GENERATION of young men is developing extreme ideas about sex from hardcore online porn.

So says Cindy Gallop, a New York businesswoman who is visiting Australia this week and is determined to change their views.

Young men think sex is "all about them" - and it's freaking young women out, Ms Gallop told news.com.au.

Blokes are expected to watch porn because "guys bond around grossness and ridiculousness", Ms Gallop said, adding that many were watching from as young as 11.

They're copying pornography's "extreme" depictions of sex in the bedroom, she said, and those porn videos don't show what real-world sex is all about: "Having a great time."

Ms Gallop is pioneering a form of "real world" porn with a website called Make Love Not Porn.

She hopes videos uploaded on her website - which she described to an American newpsaper as broadcasting only "real, unscripted, messy and even comical sex" - will change people's perceptions.

But the porn industry alone can't take the blame for young men growing up with perverted ideas, she said.

Ms Gallop said parents need to educate their children about sex as soon as they start exhibiting sexual behaviour, because otherwise porn will fill the gaps.

"It's never too young," Ms Gallop said. "Every parent should be talking to their children about sex as early as possible."

Tens of thousands of Australians are so addicted to porn they watch up to five hours a night, according to Perth researcher Dr Phil Watts. About 70 per cent of Australian men watch porn occasionally.

A May 2012 study in the Australian Journal of Medicine said 28 per cent of nine-to-16 year olds had seen sexual material online.