Ah. We have reached a developmental threshold. I thought we’d hit it before Christmas when my daughter said, ‘You know I was in mummy’s tummy? Well how did I get out?’ but that was only the mechanics of birth (and she didn’t believe me that mummy pushed her out her noo-noo). No, this question – the creation of life and the sexual dimension it implies – is altogether trickier, deeper, and represents a significant step outside of ‘that’s the way things are’ to ‘why are things that way?’ Yikes.

I must admit, I fudged the answer. I was alone with her in the car at the time, and I figured something like this ought to be discussed with her mother first so we can decide the best time, best way, and all that. To be honest, I thought I wouldn’t have to deal with the concept of procreation for a few more years at least, so I wasn’t ready, and a garbled response about eggs and seeds probably isn’t the best way to introduce a three-year-old to the mysteries of the adult world.

My mind racing, I considered implying that birds and bees had something to do with it; storks, cabbage patches, magic; even the age-old ‘when a mummy and daddy love each other very much…’; but given that bees are dying, storks are terrifying, and one of her friends has two mummies, it’s no longer that simple.

I turned it on its head and asked her how she thought they got in there.

‘I think mummy swallows them,’ she said, and we left it at that.

Phew! Dodged a bullet.

I was taught about sex at the age of four or five – penises, vaginas, sperm and eggs. While I’m not sure about the appropriate lower age, there is definitely an age where you should already be clued in – I remember everybody making fun of a ten-year-old at my school because he thought he came out of his mother’s butt. Sucked to be that guy – pooped into the world.

There’s a danger to leaving it too late, too. When I was on a bus travelling through Alabama twenty years ago, I remember seeing a massive billboard that said: ‘Talk to your children about SEX, or SOMEONE ELSE WILL!’ You definitely don’t want them learning from porn and thinking, like today’s eleven-year-olds, that that’s how people actually do it. And, of course, the consequences of a lack of sex education have been devastatingly explored in fiction, from Stephen King’s Carrie to Ian McEwan’s On Chesil Beach. Message received and understood.

But there’s a way to do it, and I know that showing embarrassment or squeamishness can send out the wrong message and lead to problems later down the line. I met a girl at university who said, ‘I’m bisexual, but I’m terrified of penises, so I’ve only ever been with girls and I don’t think I’ll ever have sex with a man, so behaviourally I’m a lesbian.’ (My response to this statement was, ‘Nice to meet you, I’m Gillan, what’s your name?’). I don’t want that kind of confusion for my girls.

And I certainly don’t want them to think sex or masturbation or specific body parts are ‘dirty’ or ‘naughty’ or ‘shameful’ either. I want them to be body confident, with a healthy sexuality free from the hang-ups that I, an awkward, sexually-inexperienced autistic bloke might pass on to them.

So I started researching this topic online (very carefully – I don’t want to be on a watch list!), and I discovered I’m a lot more old-fashioned and out-of-touch than I realised.

Today’s Parent, for example, suggests teaching a child of 0 to 2 the words penis, vagina, vulva, clitoris, bum and nipple, meaning I missed that window. It also suggest explaining to them when and where it’s appropriate to explore their bodies – gently and in the privacy of their bedrooms, apparently – which I must confess I thought was a conversation for much, much, much later on.

For the 2 to 5 age range – where we’re at now – it suggests opening up about consent, explaining it’s not appropriate for others to ask to see or touch their genitals, and not to keep secrets about this, which is definitely good advice but, God, how do you have that conversation without implying the world’s full of sexual predators? Also, now’s the time to mention sperm and egg, perhaps leaving the gory details for when they’re older.

All of this seems alien to me. Far too young, I keep thinking, let them be children a little longer before you strip them of their innocence. But other sites, like Family Education, all seem to agree on this basic framework – the proper names for genitals and where and when it’s appropriate to touch yourself somewhere between 0 and 3, the egg and sperm speech and stranger danger around 3 to 5, and the more explicit details about 6 to 8.

I’ve been living under the erroneous belief that I could sit them down in about five years, have a one-off Q&A session, then avoid the issue until their first date when they’re sixteen, with a couple of ‘women’s issues’ interventions along the way. Instead, you need to mention sex throughout their upbringing, stressing issues of consent and context, in order to create a sexually healthy adult.

I guess I agreed to all this when I became a father, and next time she asks I’ll be better prepared. Sometimes, I think it would be better if a stork delivered us fully-formed to our parents. You certainly wouldn’t have to worry about stretch marks and post-partum incontinence!