The first time we hear the phrase “best holiday ever” in How To Have Sex is during a pre-dawn swim as teenage friends Tara (Mia McKenna-Bruce), Em (Enva Lewis) and Skye (Lara Peake) kick off their booze-fuelled bender in Greece.

The last time we hear it is on the last day of their holiday, when Em and Skye burst into the bedroom where Tara has just had an awful sexual experience with Paddy (Samuel Bottomley), a young man who appears never to have heard the word “consent”.

Best holiday ever? Not so much.

“I went on a bunch of holidays like this,” says Molly Manning Walker, the London-based writer and director of the film, which won the Un Certain Regard award for a first-time director at Cannes last May. “I was a very different person when I was 16. I had long hair, fake eyelashes, I was covered in fake tan. I went to Ibiza, Magaluf, all of the places. So it’s a combination of events that happened when I was there and research that is more up to date.”

What happens to Tara is a version of what happened to her at the same age. “I’ve always wanted to make something like this, since it happened to me when I was 16, I’ve wanted to speak about it,” she says. “But every time you go into a room and you say it out loud, everyone’s like, ‘shhh’, and it really sucks the air out of the room, you know? And for me, as a victim, that’s like the worst thing you could ever do to someone, because then suddenly you feel guilty and ashamed.”

Walker is an acclaimed cinematographer, who shot the charming feature Scrapper for her close friend Charlotte Regan. They are both, she feels, part of a wave of change that’s sweeping through the industry and bringing female voices to the fore. But she’s wary, too, of how the tide can recede.

Her mother, Lesley Manning, is also a filmmaker. In 1992 she directed Ghostwatch, a 90-minute mockumentary hosted by Michael Parkinson and presented as if it were live and factual. The special on paranormal activity invited viewers to dial in with their own tales, and there are claims that the BBC received 1 million calls. It certainly received a lot of complaints, and was subjected to an inquiry about how such a misleading program could have been broadcast (even though it went to air in the drama slot, under the drama umbrella, and on Halloween, all of which should have offered clues to what was going on).

In short, Ghostwatch made a huge splash. But the backlash didn’t do Lesley Manning any favours.

“She made that when she was 29, and then her career sort of fell apart,” her daughter says. “It was super successful and then she had a really hard time. I mean, she’s still hustling now, still trying to make stuff, but she’s just had a really hard time.”

You’re 29, I note. Does that give you any cause for concern?

“Yep. Of course. I mean, I’ve grown up with the DIY scene, and I’ve seen my parents [her father is a freelance cartoonist] have no money, and that’s always been a scary thing with filmmaking,” she says. “A lot of the reason I went into cinematography was to have a bit of money. That’s a job.”

How To Have Sex started as a COVID project, when there were no jobs to be had. It sprang from a single memory from her years of clubbing on the party islands of the Mediterranean, a time that, to be clear, also includes some of the best moments of her life, in which a male friend was dragged up on stage and fellated by a stranger in front of a raucous crowd of drunken revellers.

That scene is recreated in the film, with Tara watching on in horror as the boy she imagined she might fancy, Badger (Shaun Thomas), gives himself over to the moment.

Until she started writing it down, Walker wondered if she’d misremembered it; after all, she was pretty hammered at the time. But when she met up with some of the old crew, she realised everyone had pretty much the same version of events seared into their memories.

“And I just thought it’s crazy how that would have shaped our knowledge and experience of sex, and our understanding of it,” she says. “I remember the whole crowd was yelling. We’re meant to be stoked about this? So yeah, that is kind of the root of the whole script.”

With an episodic structure and a sense of teetering on the edge of out-of-control, How To Have Sex brilliantly evokes the mood of a holiday in which the goals are pretty clear: get drunk, get a tan, get laid. But the rules of engagement aren’t, and Walker’s characters, like many a young adult in the real world, are left to grope (literally and figuratively) in the dark, often taking their clues from what peers and porn tell them they should want or allow, rather than from what feels right.

It’s far from didactic, but Walker hopes her film helps educate people, “especially young men, that they don’t need to have this bravado and pretend to know what they’re doing”.

There’s still so much shame around sex, she believes, that young people often don’t know where to turn for advice – and porn fills the void.

“You’ll never stop people watching porn,” she continues, “but if we were having more open conversations about sex and female pleasure, and about things that people often don’t speak about, then there would be less necessity to look at it.”

The first time Walker started to feel her story had wider resonance was when she was making the film in Malia, the deserted holiday town in Crete that the production took over in October and November 2022 (it looks like summer, but it was seriously cold; for all the scenes shot in swimming pools, she says, the cast were wearing thick woollen socks on their out-of-frame feet).

“Lots of women on set, and men, were telling me they realised they had been in similar situations,” she says.

There was an intimacy co-ordinator on set, and counsellors and a therapist, for anyone who was triggered by anything happening in front of the camera. “Part of the whole process of making the film was, ‘no one should come out damaged by it’,” she says. “It’s so often the case when you’ve got such an intense shoot with new filmmakers, and everyone’s still figuring out what they’re doing, that you come out the other side with a hard-done-by crew.”

But it was only when the film debuted at Cannes that Walker fully realised how it might affect people.

“We were hanging around after a screening, and there was an older man, maybe 65, pacing up and down outside, and someone asked if he was OK, and he was like, ‘I’ve just realised I’ve been Paddy before’. And in that moment, I relaxed about the other screenings, because I was like, ‘if we can do that to one person, it feels important’.”

For Walker, the biggest thing How To Have Sex does is to shift the focus from rape in its most egregious form to something far more everyday. “We really wanted to see the stuff that everyone’s gone through,” she says.

She wants men to feel included in the conversation she hopes her film will provoke, rather than to feel attacked. “The whole idea was never to use a judging lens,” she insists. “These guys are a product of their society as much as the girls are, and some of the girls are horrible to each other.

“It is obviously horrific,” she adds. “But I don’t think we can change the culture until we allow people to be like, ‘I’ve done that, and I need to change, and we need to do better’.”

How To Have Sex is in cinemas from March 7.

Contact the author at kquinn@theage.com.au, follow him on Facebook at karlquinnjournalist and on Twitter @karlkwin, and read more of his work here.

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