The author visit to the school was arranged. The school librarian and the English teacher had read his new teen novel and approved the visit. Then the head read the book. At the last minute, the visit was cancelled.

The book is my new novel Rich and Mad. Young readers know me best for my fantasy trilogy The Wind on Fire. The first of these three books, The Wind Singer, is published in a teaching edition and is taught in primary schools up and down the country.

Rich and Mad is something else. The title refers to the main characters, Richard and Maddy, who are both 17 years old. It’s a love story for, and about, teenagers. And it’s sexually explicit.

The book came about because my publisher noted the central role played by love stories in my fantasy fiction, and made a simple radical proposal: “Why don’t you write a contemporary love story?”

As I began to plan what I would write, I realised that I had a decision to make. What was I to do about sex? I could ignore it, of course, and treat my characters’ emotions in a purely romantic way; or I could hint at it, and allow my readers to imagine for themselves actions that I never described; or I could make it part of my story.

I embarked on a little elementary research. I learned that most teenagers are sexually active by the age of 16, and that we have the highest rates of teenage pregnancy in Europe. I learned that the 12-17 age group is the heaviest user of internet pornography. So whatever else might be true of my potential readers, it was clear that they were not innocent about sexual matters.

I looked, then, at the books available for teenagers to read in this area, and found that there was virtually nothing featuring teenage sexual experience. Plenty of heavy-breathing romance, much of it involving vampires, but where were the accounts of what it’s like growing up torn between punishing self-doubt and wild desires?

I decided to fill the gap. I wrote a story that follows two teenage virgins on their error-strewn, fearful, wonderful journey to a first sexual experience. It’s also a love story. Love and sex begin as separated drives, but they slowly converge. My object was to describe sex as experienced by two people who are deeply emotionally engaged. I was in the business of producing anti-porn.

This enterprise involved me writing some explicit sex scenes. I have tried to do this with a light touch, but I have also tried to be as truthful as I know how. I’m more concerned with the ever-changing stream of doubts and longings in characters’ heads than with the doings of their bodies, but their bodies exist, and I do not pretend otherwise.

The book has been wonderfully reviewed, and no reviewer has taken offence at the sexual content. If anything, my story has been criticised for being too sweet. My Rich and Mad adore each other. My teenage daughters, entirely unoffended, commented wistfully, “Do boys like Rich really exist?” And yet here was the head of a school effectively banning my book. Why?

It turned out that her concern was that the parents of her Muslim students would take offence. I respect this concern. In another school, the staff were nervous on behalf of the fundamentalist Christians among their parents. This, too, I understand.

And yet many schools have welcomed me and my book. In each one, discussion of the book prompts the students to talk about their own views and experiences. Always at the end I ask: “When did you last have a discussion like this?” Every time, the answer is: “Never”. Not in school. Not at home. I ask what is discussed in PSHE classes. “They tell us about contraception and diseases.” That’s it. The one topic that absorbs their greatest energy, the one topic that is the source of their most potent anxieties, is never raised in school.

My own experience tells me that classes of students aged 13 and over will talk eagerly about such matters when there’s a reference point outside themselves. I use my book. I describe the plot and ask their views on how credible it sounds. I invite them to tell me, not about their own behaviour but about their peer group. We talk about how long relationships last (“About a week”). We talk about the gap between boasting and reality, particularly for boys. We talk about the way boys are admired for sexual activity and girls are punished. We talk about girls having sex even when they don’t want to. About how boys cheat. About being ashamed of being a virgin. About using sex to get love.

One boy in one class told me his family were Pentecostalists, and believed sex should be reserved for marriage. He explained that he was taught to suppress any sexual thoughts that came to him. His classmates listened with interest, he wasn’t laughed at, and we then got into talk about the pros and cons of this approach. At the end of these sessions, they tell me they have never heard any of their class talk this way before.

I am aware how hard it is for teachers to talk about sex and love in class. It is embarrassing, it is personal and it is controversial. And yet, keeping this great silence does not mean our children are hearing nothing. While we remain mute, the celebrity culture is teaching our children to sexualise their appearance, and the internet is teaching them to pornify their love life. Can we afford to stand aside? Can’t we, at the very least, offer some alternative versions of love and sex?

`Rich and Mad’ is published by Egmont, pound;6.99

William Nicholson is a screenwriter of films including `Gladiator’ and `Shadowlands’, and author of `The Wind on Fire’ trilogy.