Bigots and reactionaries are like small children, in that when they ask a question over and over and over again, it is usually because they don't like the answer. "How do we stop teenage girls having sex?" is one of these questions. The answer – "We really, really can't" – is unacceptable to the moral mumocracy, who become incensed when any policy is proposed that appears to prioritise young girls' safety and autonomy over those excellent, tried-and-tested methods of preventing teenage pregnancy: shame and ignorance.

This week, a scheme is being piloted on the Isle of Wight that will allow girls as young as 13 to have access to a month's supply of the contraceptive pill over the counter in pharmacies. The Daily Mail has gone bonkers, which might seem surprising, given the suggested attitudes of its readers both to teenage pregnancy and to abortion. All becomes clear, though, when one understands that the greater social evil is teenage girls having sex at all. The scourge of the underage slags must be stamped out by any means necessary, as long as those means don't involve actually providing useful sex education.

Simply perpetuating the fear of pregnancy by making it harder to get access to contraception is no more likely to stop teenagers shagging each other than a conversation about inbuilt obsolescence and sweatshop labour is going to stop hipsters buying MacBooks. (For the record, I'm typing this on a MacBook.) For some, the main objection to contraception being made available in pharmacies is that it means that young girls will be able to get hold of prophylactics without first talking to their parents, who, of course, are the proper gateways for all teenage sexual behaviour. I don't know about you, but when I first considered becoming sexually active, I couldn't WAIT to talk to my mum about it.

"Mum," I said, "I'm considering becoming sexually active." "That's great news, honey," she said. "Let's go down to the family doctor and get you a coil and some banana-flavoured lubricant!"

There are others, including Mr Stephen Fry, for whom the whole idea of females being sexually active of their own volition is incomprehensible, much less young girls. Surely they should be satisfied with being passive objects in a culture that surrounds us with images of adult women posing as schoolgirls in order to make men excited? Surely actual pleasure doesn't register on the radar of these creatures, who are, as we know, comprised entirely of sugar and spice and all things morally circumscribed? Surely their junior pole-dancing kits should be enough?

Then there are those who believe that shame alone should be enough to keep girls from dropping their knickers: shame and the fear of pregnancy. Nobody, it should be noted, seems to have any problem with the idea of teenage boys having sex, although several recent studies have shown that in nearly all cases of underage pregnancy, a male was involved at some stage.

As Rowenna Davis observes in the Guardian, there has been precisely no outcry about young boys buying condoms, which can and does occur at every chemist in the country. The idea of underage boys having sex is unthreatening: the notion of underage girls having sex is unthinkable. Teenage boys buying condoms are responsible: teenage girls being allowed to have control over their own fertility is outrageous and morally wrong.

There are, unfortunately, reasons besides lusty adolescent jollies why some very young women might need access to contraception. Some will be being pressured into sex they don't want to have. Some will be the victims of violently coercive as well as statutory rape. And some will be being sexually abused. Approximately 15-25 per cent of women, and 5-15 per cent of men, are sexually abused as children, usually by family members or family friends – another valid reason for some young girls not wanting to ask their parents for the Pill.

The Mail and other moral tub-thumpers have lots to say about paedophiles and playground perverts, but nobody wants to talk about the far more uncomfortable fact that sexual and physical abuse of minors by the people who are meant to be responsible for them is endemic in our society. It happens in every town, on every street, every day. So far, our only comprehensive response to this architecture of abuse has been to heap shame on the sexuality of women and children, as if it were somehow all our fault.

It is, as always, about control. Objecting to young girls having easier access to the Pill is part of a frantic cultural paranoia about female sexuality in general, particularly developing female sexuality, which is treated as a horrifying disease rather than a natural part of growing up. If we really wanted to protect the "innocence" of young women and girls, we would stop slut-shaming them and reserve our outrage for the adults and young men who rape, intimidate and abuse them as a matter of routine. It's about control, and nothing else.