I’m not sure at what age squeamishness about sex kicks in but I reckon the po-facery starts round about the point you stop laughing uproariously the moment the lights go up on Live at the Apollo.

Instead, you find yourself feeling irritated by stand-ups’ preoccupation – obsession! – with masturbation. Dating stories are always amusing. But must they go on quite so much about (whisper it) vaginas?

It’s not shocking. It’s far worse than that; juvenile and boring. Never before has switching over to Newsnight felt so much like gratefully crossing the Rubicon.

Sex – or at least the sort of sexy sex worth joking about – is the preserve of the young. Always has been. Not that midlifers and indeed lifers don’t indulge. But for us, it is just that: an indulgence, demanding as it does valuable sleep-time, energy and above all spadefuls of goodwill.

But not every day. Week. Fortnight. (Fill in as applicable). So how in the name of Debbie Does Dallas are we expected to talk to our children about porn before we hand over their first smartphone?

The Children’s Commissioner Rachel de Souza has urged parents to address online porn with their children as early as the age of eight. Eight! I know? You first.

A panel of young people told her that pornography shouldn’t be treated as a “taboo subject”. Instead parents should calmly explain why watching adult content can be harmful.

“When I had ‘the sex talk’ with my teenage boys they were patronising enough, but trying to tackle them about the dangers and distortions of porn was hopeless,” admits my friend. “They shut me down by rolling their eyes and sighing,” admits another. “It doesn’t help that I’m not sure what I can materially do.”

Frankly parents are eclipsed by peers and role models. In recent days the Grammy-winning singer Billie Eilish has spoken of the recurring nightmares she suffered after watching abusive porn and how it impacted on issues of consent during her first sexual experiences.

“I think porn is a disgrace. I used to watch a lot of porn, to be honest. I started watching porn when I was, like, 11,” the 19-year-old said, saying it helped her feel as if she were “cool”.

“I think it really destroyed my brain and I feel incredibly devastated that I was exposed to so much,” she added.

“The first few times I had sex, I was not saying ‘no’ to things that were not good. It was because I thought that’s what I was supposed to be attracted to.”

In case you’ve never seen online porn – and my eyes welled up with tears in the course of research – it’s horrific and sad and enough to make mothers of daughters like me want to Rapunzel them inside ivory towers indefinitely.

This isn’t porn as my generation knew it, comprising dog-eared magazines passed around behind the bike sheds.

It isn’t vanilla kinkery of Nine and a Half Weeks in which Kim Basinger was bathed in the icy white light of the fridge as Mickey Rourke smeared his supper all over her body. Impossible to recreate these days, what with the thousands of food miles going to waste and the fact modern appliances beep endlessly if the door is left open.

No, this is 2021 online porn. Terrifying. Dominant. Violent. There is choking and spitting and angry misogyny. Women are spatchcocked, degraded, used. And all freely available – and most saliently, free – at a few keystrokes on a phone.

Parents can cluck and fuss but most kids first come across porn by accident. And once those images are seared on their blameless retinas there’s no turning back.

Excess consumption of pornography poisons personal relationships, destroys intimacy and harms self esteem. Not just self esteem; there is never any foreplay. Viewers are repeatedly presented with scenarios where sex is “done” to a woman, who is then discarded, having fulfilled her only purpose.

I’m not trying to abdicate the responsibility of parents; but we are the supply teacher nobody listens to. I’ve lost count of the naggy ‘No Sexting’ lectures I’ve dispensed from the get-go. I share dismal anecdotes about the times I ought to have listened to my own gut rather than someone else’s blandishments.

But children don’t believe a word their parents say. What do we know? That was sex in the olden days. Old sex. Ewww!

It is Billy Eilish who can help make a difference by telling her truth. It is TikTokers who can help alter the perceptions of porn by poking fun at it. Above all it is the duty of platform providers to make it harder for children to access porn for free. I struggle to comprehend why they don’t already. But to concentrate their minds, the Online Safety Bill is currently being scrutinised by Parliament.

A number of new protections have been recommended, including the requirement that all pornography sites will prevent children from accessing their content, which would involve introducing age verification. This must err on the side of stringency rather than entering a date of birth in a pop-up form. Frankly I’d push for fingerprint-and-face recognition. Possibly a written application to be stamped at the local Post Office.

If we don’t stem the tide of aggression and exploitation our young people will suffer terrible consequences. In the toxic world of extreme online porn there is no happy ending.