During what will prove to be 2020’s most astonishing opening sequence – even this early in the year – Otis Milburn (Asa Butterfield) tries and fails to control his newly discovered sexual urges in a scene that ends in excruciating embarrassment in front of his therapist mother (Gillian Anderson).

Days before the second helping of the Netflix comedy-drama was released, executive producer Jamie Campbell, casting director Lauren Evans and location manager Midge Ferguson took part in a Q&A, following the Cardiff screening of the first episode of the new eight-part series.

Season one was a huge critical success and almost certainly a commercial hit too for Netflix, although the US streaming company is famously reticent about releasing viewing figures. “We didn’t have any idea that people would respond to the show in this way and, particularly, that the breadth of audience would be as it is,” said Campbell, creative director of Eleven Film, which makes Sex Education.

Despite being set in a school full of sex-obsessed teens, the show attracts “an audience which is very youthful and an audience which is very senile – and lots of [people] in between,” joked Campbell. “People think it has something very contemporary to say, which can apply both to very young and old people.”

The series, he added, is not “didactic” but is “truthful and emotionally open, which people like”.

Campbell praised series creator Laurie Nunn. “The conceit of the show is very unusual and shouldn’t work,” he said. “It allows you to be broad comedically but also go to some quite dark emotionally, deep places.”

Sex Education’s cast is a mix of the famous and experienced – Anderson, Butterfield and, new for season two, Anne-Marie Duff – and first-timers.

Discussing how she cast the show, Lauren Evans admitted that, initially, “it was a daunting challenge”. “With a younger cast… some of whom had never [acted] before, it’s about feel… and trying to assess quickly whether they’ve got potential.”

Cast diversity, she said, was critical. “It was hugely important to find an eclectic ensemble that was representative, so everyone could see themselves on screen.”

The sexually explicit nature of the show led to Evans enduring “some of the most embarrassing phone calls of my life.

“These were young actors and I had to have a conversation [with them], making it transparent from the beginning that it’s got sexual content… and, especially in this climate, to make sure everybody feels that they’re armed with the knowledge of what the show’s about, how we’re going to shoot it and what is required of each character, so they could make an informed decision before they committed [to it].”

An integrity co-ordinator was brought on board for filming “so that all these scenes of a sexual nature [could be] broken down and almost choreographed. Everyone talks through what they are and are not comfortable with – everyone has a voice,” Evans added.

Sex Education is set in the fictional Moordale Secondary in Caerleon, South Wales. The series makes the most of the Wye Valley’s many beauty spots, few of which have been seen in TV drama before.

“I found most of the locations driving around and getting lost,” explained Midge Ferguson, who grew up in nearby Monmouth.

“A lot of shows end up using the same old locations – if you’ve ever been down Bute Street in [Cardiff] Bay, you know it’s had the shit shot out of it. Trying to find [places] that are fresh as well as aesthetically brilliant is what I’m after. Wales is just full of fantastic places.

“I had a good chat with the director Ben Taylor and the [production] designer about their thinking, so I had an idea of what I was looking for. Then, I literally headed off in a direction that I thought I might find them. I had good days and bad days.”

“Midge took us around in his car and showed us [some locations outside] Caerleon,” recalled Campbell. “He was showing us stuff that we were getting blown away by.”

Working for Netflix, said Campbell, has been “unequivocally a great experience”.

He continued: “They really backed the script and Ben’s creative vision for how to shoot it, and told us to get on with it and make it the most ‘authorially’ pure show that we could make. That is an unusual approach. Most broadcasters ask you to shape it for a particular demographic.”

“Sex Education season two screening plus Q&A” was the first joint venture between RTS Cymru Wales and Bafta Cymru. It was held at the Chapter Arts Centre in Cardiff on 15 January and chaired by BBC Radio 1 presenter Steffan Powell. Edward Russell produced the event for RTS Cymru Wales. A longer report will appear in the February issue of Television.