I mean, what do you say? I'll admit I did smirk, thinking of the fathers of all the multiples I know whose backs might have straightened a little with pride, but then I thought, no, break it down. I believe kids need answers to their questions - even if sometimes you have to bluff your way through an explanation because you feel they aren't ready to hear the real one.

But in this case, and with every question that has come up about sex since they were little, there's always some information that has been OK to give out.

I asked him what he meant by do it (and perhaps I should be more upset by the fact that we've seemed to have moved on from ''special cuddle'' to ''do it'') and he had the mechanics of that down pat. Insert Tab A into Slot B, so to speak, and ''rub it around''.

So then I tried to explain that, yes, basically that's what happens and during the rubbing, the mummy's and daddy's bloods mix together (not sure if either of us is ready for semen just yet) and sometimes there's extra blood and that's how twins are made.

He seemed happy with that and his next out-of-the-blue question involved my arrival in Canberra and if I had never had come to Canberra would he be living somewhere else. Bugger him, I thought. So I told him that if I had never had come to Canberra I never would have met their father so our bloods would have never mixed to make them, and if I had another husband I'd have different kids and they wouldn't even exist. Take that.

This is something that always fascinated me as a child once I worked out what was going on. That if ''it'' didn't happen between my parents at the specific time it happened, I would never have existed. Not that I thought a lot about my parents having sex - god, what child does? - but I quickly worked out that if dad had been away that night, or mum had been asleep, I would not exist. It makes you realise how special and perhaps, at the same time, how ordinary you really are. A product of lust and luck, that's all.

There has been a bit around this week about sex education and when might be the right time for the birds and the bees talk.

The Australian Curriculum, Assessment and Reporting Authority, the body in charge of shaping the national schools curriculum, has indicated that years 5 and 6 are most appropriate to introduce sex education to children in schools.

An earlier recommendation suggested years 3 and 4, but after consulting with parents the draft was amended. The curriculum is still in development and will be released for public consultation in February.

I can't really remember much happening in primary school when I was a child. It was the 1970s, however, and topics like that were better talked about at home than at school.

I do remember heading along to the annual school talk where the year 6 children would be ushered into the hall along with their parents. We watched a film (which, thinking about it now, might have been the same one we watched during our pre-marriage classes - and don't get me started on sex education as a 20-year-old), some brave kids asked questions, some pamphlets were handed out and you sat in the car in an embarrassed silence during the trip home After that, it was never spoken about again.

Come high school it was friends and Dolly magazine that helped educate me. At school we did PD classes, which was an abbreviation for physical development but we always called them VD classes - OK it was funny when you were 13 years old. Every week some poor relief teacher (more often than not, it always seemed to be the relief teachers or the young male teachers who were fresh out of teacher's college), who got lumped with this class, would guide us through the great journey of life.

In the early years it was all about being positive and then, in about year 9, it got a little hardcore. Perhaps I was a naive, but I remember one class where we were shown a range of contraceptives, including condoms, diaphragms, applicators for creams and potions, intrauterine devices and the pill. It was quite confronting but we got into it eventually. Boys blew up condoms like balloons - I think someone might have tried to get one over their head - and there were bananas and cucumbers. When the principal found a couple of us, me included, washing out spermicide applicators under the bubblers toward the end of class, and we told him what we were doing, I'll always remember the look on his face.

But I was 14 years old by this stage, not nine. But is nine the new 14? I had no idea about ''doing it'' when I was nine years old, I'm sure. There were no songs about passion in your pants or sexy ladies nor risque video clips on a Saturday morning - only Road Runner and the Coyote or The Flintstones. Life was more innocent. Perhaps it was easier to navigate for all of us, parents as well as children.

While schools will do what they can, when they can, as parents we need to think about when the best time is for our own children. It may well be earlier than years 5 and 6. We need to be honest with them, to answer their questions, to call a penis a penis, and let them know that sex is a very enjoyable part of life. Most importantly, we need to teach them that there is so much more to it than the sex.

Regardless of your own sex education, our children are growing up in different times and if we leave it up to the schools then we have failed them.

Twitter: @karenhardyCT