Why Gwyneth Paltrow and Goop have released an explicit sex book

Gwyneth Paltrow, 45, says there was a need for the publication stating "sexuality is an important topic." Photo / Getty Images

It might be imagined that Gwyneth Paltrow's middle school aged children would be a little embarrassed by her latest project.

The Oscar-winning actress turned lifestyle magazine boss is busy promoting a new book about modern sexuality.

But, says Paltrow, the thought of her children learning about "the birds and the bees" was one of the reasons she took on the project.

"We're living in a time where there's so much access to everything," she said on Good Morning America on Tuesday morning. "I have a 12-year-old boy and I live in fear that he's going to learn all about sex from the internet."

Gwyneth's newly released tome, titled The Sex Issue: Everything You've Always Wanted to Know about Sexuality, Seduction, and Desire, retails at $26 for the hard-back edition on Amazon.

The 45-year-old said she was excited when the book was proposed to her, adding the "editors came and said we want to write kind of a new Joy Of Sex for the modern person."

She said there was a need for the publication.

"Sexuality is an important topic," she added. "And I think sometimes people think it's taboo and they don't want to talk about it."

Paltrow has shared that she lives in fear of her son learning about sex from the internet. Photo / Goop

Paltrow also talked about her children's reaction to her impending wedding.

"They are excited," said the mother of daughter Apple, 13, and 12-year-old Moses, born during her first marriage to Chris Martin.

Paltrow is engaged to Brad Falchuk, a television writer and producer behind shows such as Glee and American Horror Story.

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Happy Valentine’s Day to all especially @bradfalchuk ❤️

A post shared by Gwyneth Paltrow (@gwynethpaltrow) on Feb 14, 2018 at 5:39pm PST

She said the wedding experience was a new one for her.

"Chris and I eloped so I've never had a wedding or any of these fun things," said the Goop founder.

"It's a very happy time, I have to say."

Paltrow, 45, has not revealed the plans for her wedding day, although she did celebrate her engagement with a huge Hollywood party, attended by her showbusiness friends.

"I'm super lucky in that I have these incredible relationships in my life," she said on Tuersday. "To feel that love and support from our community is really, really special. It just makes me cry every time."

Paltrow and Falchuk, 47, announced their engagement in Goop magazine in January, after months of speculation about their romance.

*The Sex Issue: Everything You've Always Wanted to Know about Sexuality, Seduction, and Desire retails for US$26 on Amazon.