Secondary school sex education lessons used to typically involve a middle-aged teacher blushing nervously as she rolled a condom over a cucumber in front of nervously giggling teenagers.
Today's coital curriculum sees children taught about the darker side of the birds and the bees. Sex crime detectives are going into the classroom to speak about the risks of more modern phenomena such as internet dating, date rape and gang rape.
The teaching of sex education is believed to have begun some time around the Second World War, when schools began educating boys who would soon become soldiers about the debilitating effects of syphilis and gonorrhoea. Sex education in the 1950s and 60s was limited to this and the perceived dangers of onanism. The emergence of HIV and Aids in the 1980s meant that the focus of theses lessons shifted to the importance of safe sex.
Latterly the discussion has been about when, rather that what, should be taught, with some suggesting that children are being taught too young. Just before the election this year the Labour Government dropped a plan to make sex education lessons, which currently focus on puberty and reproduction, compulsory.
Until now little has been taught about sexual assault. Following the cases involving serial rapists John Worboys and Kirk Reid – in which the Metropolitan Police was strongly criticised for multiple failings – Scotland Yard reorganised its specialist "Sapphire" units investigating sex crimes under one central command, and decided to tackle the prevention of sex crime as well as its investigation. The newly structured unit has teamed up with schools across London, particularly in the borough of Lambeth.
Detective Chief Superintendent Caroline Bates, who heads the Sapphire Unit, said that they want to address the problem of schoolboys forcing girls to have sex. "There are young men who do not seem to realise that they are likely to get arrested for certain types of behaviour, such as inducements to perform sex acts," she said.
"Young men are telling girls, 'If you do not do this to me and my mates then I am going to put photographs of you on Facebook.' That is blackmail but it is often seen as just a part of life. We are telling people that they have a right to say no."
She added: "We are talking to young men about the risks they are taking as offenders and asking if they understand what rape is."
She added that they spoke to the schoolchildren more generally "about self-respect and about acting responsibly", explaining: "If they are going out we tell them to make sure one friend stays sober and to stick together as a group. And we warn them that if they decide to take drugs then that will make them more vulnerable. We also advise them on what to do if using internet dating sites.
"We don't preach to them and we appreciate that their sex lives are their own and at the end of the day it is up to the individual, but we tell them how to stay safe from sexual assault."
Det Ch Supt Bates said that children as young as 12 were coming to them to report sexual assaults.
"There is a big increase in the sexualisation of children, whether that is about the clothes sold at certain shops or the magazines which talk about celebrities' sex lives but are clearly aimed at children," she said. "The internet makes all of that instant. Some of these kids live their lives around the internet."