It is just after 3pm on a school day sometime last century. Apparently I have a very tense look on my face. I pull up on the side of the road with my late primary school-age daughter and ask urgently: “Have I ever talked to you about what the clitoris is for?”

“Mum,” she reminded me this week. “I was only 12.”

Of my many unbelievably awkward parenting moments, this might take the gold for gormless. I had long used the car journeys as a place to have serious conversations, recommended to me by a friend who said kids found it hard to have these conversations face-to-face.

Now 20 years on, my kids can joke about what their parents told them about sex. They can tease all they like (and they will, until eternity) but these are the uncomfortable conversations we all need to have. As Juliet Richters, honorary professor at the Kirby Institute and long-time researcher into sexuality and all who sail in it reminds me, the question about when should you start to talk to your kids about sex has the same answer as the question about when to begin saving for a house. You should have started 10 years ago.

Sigh. Look, I’d had zero discomfort with the “how babies are made” conversation because two geniuses had invented a pop-up book, complete with erect waving penis and near-enough-is-good-enough vaginal architecture. It was my bible when explaining to children the very basic facts of life. As one of those annoyingly earnest parents, I can see I put my children through a lot. But was it enough? I can’t say I felt enormously comfortable talking about orgasms with them but did it anyway. Since they were all going to be participating in sex as recreation, at least they had to know the bare bones of how to make it enjoyable for themselves and their partners. For those of you clicking your tongues at the sheer audacity of suggesting young people have sex before marriage, let me remind you that you did. The majority of teenagers become sexually active between 15 and 19.

On the cusp of their early teens, how well can we – do we – communicate with our children about intimacy and love, about consent and pleasure?

Not well enough. On Monday, Chanel Contos, the powerhouse who made it possible for young women to share their shocking stories of sexual assault, launched a new action – a petition to improve the sex education curriculum and reform consent laws, which MPs from across the political spectrum support. But like reading, writing and arithmetic, parents have to do the support work. Just as we go through those endless readers our kids brought home from kindy onwards, we need to talk about sex, pleasure, consent, the right to say yes and the right to say no.

Here is the bad news. The teenage years are too late. By then, they have started to rebel. They would rather share information with each other than with their ageing embarrassing parents, according to Christopher Fisher, sex education researcher and associate professor at La Trobe University. By the teenage years, they should know that sex is both fun and funny. That it is not as portrayed on sitcoms or on porn. And that it can be the most deeply pleasurable activity, with an attendant explanation of both the clitoris and the glans of the penis. And why is pleasure important? Once you recognise that it is about more than your own sensations but also about your partner, no matter how temporary, sex becomes both consensual and sensual. It is no longer about keeping score but about excitement and contentment.