Success can be a strange whirlwind; the sort of thing you only acknowledge in hindsight. For Sex Education creator Laurie Nunn, it was an innocuous work email chain that made her take stock of the improbable phenomenon she had created.

“There was an email for season two that was to do with costumes, and the title of it was just, ‘Vagina Hats’,” she says, with a light, disbelieving laugh, in an oddly barren Holborn hotel room. “At that point I thought, ‘This is strange. This is a really strange job.’”

Indeed it is. But perhaps one of the greatest victories of Nunn’s acclaimed show — which, at its core, is the funny, filthy tale of socially awkward sexual savant Otis Milburn (Asa Butterfield), who doles out intimacy advice to his dysfunctional teenage schoolmates — is that it turns ostensible strangeness into something vital, rousing and compulsively watchable.

With a 2019 debut season that was devoured by 40 million Netflix viewers in one month, it is one of those rare shows that manages to walk a wobbling tightrope between sneaky creative boldness and genuine mass appeal. It’s a thrillingly progressive, thorny exploration of modern sexual mores, sprawled across the soothing, John Hughesian world of locker-lined high school halls and suspiciously enormous houses in the fictional town of Moordale.

Which is another way of saying that the pressure was truly on Nunn, 33, when it came to the eight-part second season, which launched (vagina hats and all) on Netflix earlier this month.

As those who have already sprinted through it will now know, the new episodes begin with an uproarious montage concerning Otis’s new-found fondness for al fresco self-pleasure, culminating in an, um, ill-timed interruption from his sexual therapist mother Jean (Gillian Anderson). Was Nunn deliberately trying to ratchet up the shock factor, as quickly as possible?

“I definitely knew that the show needed a strong opening,” she says, smartly dressed in a dark blazer and frilly roll neck. Her voice is just slightly tinged with the Aussie accent that betrays a childhood partly spent in Melbourne. “That scene is actually based on a story that a friend of mine told me. It stuck in my head as such a funny, horrific thing. But it also tapped into that story with Otis; he’s a bit of a late bloomer [and now] he’s hit the part of puberty where he feels like he’s lost control of his body and his brain, but he’s still trying to be a good young man.”

This tussle — between reason and the hormone-addled monster of adolescence — is just one of the arresting themes strung through a season that also covers (deep breath) chlamydia, bisexuality, middle-aged desire, douching in the gay community and, memorably, baba ganoush-based dirty talk.

However, Nunn (who, alongside the show’s other writers, works closely with intimacy co-ordinator Ita O’Brien) is conscious that Sex Education’s unflinching frankness never tips over into prurience that may worry actors.

“We’re constantly having open conversations, navigating the sensitive material, and if anybody did feel uncomfortable then it’s a very safe space for them to be able to voice that,” she says. “I also have a rule that sex scenes have to push the story forward or be educational in some way. That stops the show ever teetering into a gratuitous space or being titillating which, when you’re dealing with teenage characters [is a line] you have to tread very carefully.”

Last year, Game Of Thrones’s Emilia Clarke spoke of her “terrifying” early nude scenes on the show and inadvertently launched a wide debate about the pressure placed on inexperienced female actors to strip off on screen. Was Nunn conscious of this?

“It’s something I take very seriously,” she says. “Working with the intimacy coordinator is key to it. I feel that there’s a very interesting conversation to be had about whether we need as much gratuitous nudity on screen or whether we could pull back on that. Not just in our show but the industry in general.”

Nunn feels that there is a “purpose” to the show’s graphic content, both dramatically and — as per its name — educationally. Her decision to make horny sci-fi obsessive Lily (Tanya Reynolds) a sufferer of a sexually inhibiting condition called vaginismus has led to “quite a lot of messages” from grateful sufferers who didn’t realise they had a highly treatable medical condition. Tellingly, one of the most praised subplots from this new batch of episodes concerns a character who experiences a traumatising sexual assault that she initially tries to brush off with humour.

Sex Education 2: In Pictures 8 show all Sex Education 2: In Pictures 1/8 2/8 3/8 Asa Butterfield as Otis Milburn and Ncuti Gatwa as Eric Effiong Netflix 4/8 Kedar Williams-Stirling as Jackson Marchetti Netflix 5/8 Aimee Lou Wood as Aimee Gibbs and Emma Mackey as Maeve Wiley Netflix 6/8 Gillian Anderson as as Dr Jean F. Milburn Netflix 7/8 Tanya Reynolds as Lily Iglehart and Patricia Allison as Ola Nyman Netflix 8/8 Connor Swindells as Adam Groff Netflix 1/8 2/8 3/8 Asa Butterfield as Otis Milburn and Ncuti Gatwa as Eric Effiong Netflix 4/8 Kedar Williams-Stirling as Jackson Marchetti Netflix 5/8 Aimee Lou Wood as Aimee Gibbs and Emma Mackey as Maeve Wiley Netflix 6/8 Gillian Anderson as as Dr Jean F. Milburn Netflix 7/8 Tanya Reynolds as Lily Iglehart and Patricia Allison as Ola Nyman Netflix 8/8 Connor Swindells as Adam Groff Netflix

“That storyline came from a very personal experience in my own life,” she says, her voice dipped low. “So it was something that I knew I wanted to write about in a sort of cathartic way.” It’s a plot that also ends with a Breakfast Club homage that can be read as a pointed middle-finger to the critics that found the era-less, Americanised aesthetic of the first season (it’s actually shot in the Wye Valley in Wales) bothersome.

For Nunn — who was born in the UK, moved to Australia at 14, and returned to Britain at 23 to study an MA in screenwriting — Sex Education’s dreamlike, Mean Girls-indebted look is both a reflection of her teenage dislocation and an integral part of the show’s DNA.

“I think the hook of Sex Education is so heightened that it always needed a heightened world to match it,” she says. “I mean, it’s about a kid who’s giving out sex advice in a toilet cubicle; there’s not a social-realist version of that show.”

To Nunn’s mind, Moordale is “like a teenage utopia”. There’s certainly something hopeful about the fact that it is a wildly diverse, Laurence Fox-baiting rural enclave peopled by black jocks, lesbian parents, teenagers with disabilities and breakout star Ncuti Gatwa’s openly gay African character Eric. All of them are matter-of-factly presented as flawed people who are much more than ciphers for their under-represented communities.

“Because it’s a teen show, and it’s about that universal feeling of being 16, it’s really important that people see themselves reflected on the screen,” she says. It’s a diversity that extends to the team behind the camera, too (Sex Education’s writers’ rooms have been predominantly female and notably BAME), and Nunn, especially in light of the controversy around the very white, very male recent BAFTA nominations, credits Netflix with helping make this possible.

“Kate Herron, who directed on our first season, had only made short films before and now she’s directing a Marvel show in America,” notes Nunn. “It really takes somebody like Netflix to take a risk. But I do think that it’s a combination of making sure that new talent, myself included, is supported.”

Amazingly, it’s not yet been confirmed whether that support will officially extend to a third season of Sex Education. Nunn (a north Londoner who can normally be found, on her rare days off, at Islington’s Screen On The Green) has already started writing episodes, but is understandably tight-lipped about what will become of Otis, Eric, Jean, Emma Mackey’s Maeve and the various plot seeds frantically scattered in season two. But, as our time comes to an end, she confirms that there’s one teen show trope she won’t explore.

“I feel like I probably wouldn’t want to take them to university,” she says, smiling wryly. “You know, like in Dawson’s Creek where it got to the point of, ‘I think you guys are 40 years old’.” She laughs. “But I love writing these characters, and so I think there are more stories.” More stories. More sexual proclivities. And, you’d wager, more very bizarre email chains.

Sex Education season 2 is now available on Netflix