Everyone remembers their first mates holiday. The sweaty, vomit-smeared vibes of the Xanthi strip cannot easily be wiped from memory. You probably got sunburnt. You definitely drank too much. And with any luck, you snogged your way to a vacation romance as well. Good times all around. New teen drama How To Have Sex, director Molly Manning Walker’s debut, tells a different story though – one where the dream adventure with your pals quickly (and suddenly) becomes a nightmare.

Tara (Mia McKenna-Bruce), Skye (Lara Peake) and Em (Enva Lewis) are three school friends from the south of England. They’ve just finished their GCSEs and to get away from impending results day doom, they’ve hopped on a cheap flight to Malia in Greece – where exams don’t exist and the only paper you need to worry about is the little ticket you’ve just bought for that day’s boozy boat party in the Mediterranean sun.

Tara is the baby of the group. She’s the youngest and, it’s revealed by tactless bestie Skye, still a virgin. “No one cares… it’s very chill,” Skye tells her one day during pre-drinks with an older group of partiers they’ve cosied up to. Tara, scandalised that one of the boys might hear and she’ll be outed, quickly silences Skye: “Why bring it up then?!” It’s a familiar situation for anyone who’s, well, ever been young, but Tara doesn’t appear to need convincing. She seems much less bothered about having sex than Skye thinks she is.

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This is the happy part of the film. The bit where they down shots at the bar, hold each others hair back to vomit and snaffle fries on the walk back home to their budget hotel apartment. Soon though, a disturbing, unwanted sexual experience will ruin this defining moment in Tara’s life – and raise some vital questions on consent in our supposedly more enlightened modern era.

This week there are three brilliant movies about young women hitting cinemas (the others are Kitty Green‘s The Royal Hotel and high school drama Bottoms), but you should pick How To Have Sex because of its star, Mia McKenna-Bruce. Recently nominated for a BIFA (British Independent Film Awards) alongside genuine A-listers Jodie Comer and Tilda Swinton, the south London-born actor captures perfectly the chaotic excitement of Tara’s age, as well as how quickly that feeling can change to suffocating social anxiety. She’s not very well-known, and if you do recognise her it’ll probably be from her days in Tracy Beaker TV spin-off The Dumping Ground. This is her first chance to lead something more grown-up though, and she grabs it with both hands.

As upsetting (and, in some cases, triggering) as How To Have Sex undoubtedly is, there’s also a lot of joy to be had too. For every shot of Tara, bleary-eyed and fighting back tears, there’s a matching one of her cackling along with Skye and Em, lagoon-blue WKD in hand, thumping bass in the background. Crucially, (and it’s not a spoiler to say), the film ends on an upbeat note, which was important to its star. “We wanted to show that there was a light at the end of the tunnel,” she told NME last month, “and that it’s gonna be ok. It’s possible to carry on past any trauma.” Hope, then, is the film’s lasting message. Hope that it’ll spark much-needed conversations. But also hope that they won’t be so needed in the future.