"Pass this rose among you, girls." Twenty pairs of hands dutifully passed the red rose around the classroom. "Now look," our teacher smiled sadly as she held up the flower once it had been returned to her, "how shabby and faded it looks. That's what will happen to you if you have sex." That was the extent of sex education at my convent school circa 1975. I don't know how many of my classmates (all girls) ended up pregnant as teenagers; but I know I am grateful to my Swedish mother, who took a far more prosaic line on reproduction - lots of anatomical drawings and technical names - than my teacher did with her floral euphemisms. I didn't mind looking like a faded rose, but "vaginal penetration" was a real turn-off.
Most teenagers in Britain don't have Swedish mums, though. And it shows.
A newly published Social Exclusion Unit report points out that, once again, Britain tops the teenage pregnancy charts for Europe. To solve the problem, the unit recommends a punitive package: single teenage mothers should not get council homes, it says, and they should attend job interviews under the "single gateway" pilot schemes. Nothing new there: the scapegoats for teen sex have always - by nature or by custom - been the girls.
But for once, boys are being singled out for some punishment, too: the Child Support Agency is to pursue fathers of babies born to teenage girls. They will have to pay £5 a week for 18 years - whether they have a job or not - to the mother of their child. And parenting and sexual-health classes will be made compulsory in all young-offender institutions, where up to a third of male inmates have fathered children.
Hallelujah! The powers that be seem finally to have realised that it takes two to tangle and that in the blame-and-shame ritual that constitutes our policy towards teenage pregnancies, girls aren't the only culprits. Yes, there are teenage girls who will use a baby to gain occupancy of the council-estate flat. Yes, there are girls who see having a baby as no different from buying a doll - or a Furby, which weeps and asks for food. But there are boys out there who will wham-bam-thank-you-ma'am their way through school. Boys who will bully a girl, or get her drunk or high, in order to have their way with her.
And what penalty do these boys suffer? They see the girls they have impregnated and dumped pilloried by papers and pundits or pushed into giving up their baby for adoption - while in the schoolyard, the "studs" win kudos for their prowess. So why should they stop having fun when there's no price attached? No wonder the teenage pregnancies in this country continue to soar.
It is fashionable to look elsewhere - the Netherlands is a favoured yardstick - for successful campaigns against teenage pregnancies. Yes, they have more and better sex education at school; and there is far greater parental openness in discussing sex with children.
But equally important, Dutch tabloid headlines do not blast lone teenage mothers as ours do so frequently; nor does the Dutch prime minister pen jeremiads about "why we should stop giving lone teenage mothers council homes", as Tony Blair did in the Daily Mail this week.
To stop the spiralling of teenage pregnancies, we cannot afford to teach couples under 18 about mutual respect and responsibility while we continue to scream at them from every news kiosk that only one of them is to blame. We cannot demand that boys change their behaviour when only the girls' is under scrutiny.
In this area, more than in any other, we need to adopt an inclusive approach: it's not enough to stop single teenage mums. We have to stop single teenage dads, too.