“Have you ever ridden a motorbike? - No - Have you ever been out with a biker? - Me, with a biker? No!” Pillion, Harry Lighton's first feature-length film, unveiled in Un Certain Regard at the 78th Cannes Film Festival, is a particularly daring immersion. If you're a fan of political correctness, don't bother, because the English filmmaker tackles his subject head-on and explores in explicit detail the workings of a relationship of total domination and submission, giving his two lead actors extraordinary roles. Nevertheless, when feelings get involved, nothing is so simple; beneath the implacable, even disturbing surface of his subject, which flirts with Stockholm syndrome, the director finely crafts the emotional mechanics of his story and injects it with a saving humour (which may not make everyone laugh, however).

“Before I met Ray, I was innocent in every way.” For virgin Colin (Harry Melling), a young man still living with his parents in the outer suburbs of London, whose job is to put fines in car parks and whose few hobbies include singing in the pub in a small choir (pinstripe suit and straw hat), the appearance at Christmas of the very handsome biker Ray (Alexander Skarsgård), who slips him a note with a date for the next day, is a stunning yet stressful gift from heaven.

Encouraged by his mother (who is seriously ill) and supported by his father, Colin “tries something new”, but he has no idea of the strange arrangement he will have to make in order to enter Ray's life. Ray has detected an aptitude for devotion and obedience in Colin that he's going to take to extremes... And so our innocent boy is thrust into a world of roaring engines, shaved heads, Arlen Ness suits, rigid daily rituals and very special outings to the countryside with a group of “mates”. And what about love? Colin will try to get a glimpse of it and find out more about his secretive partner, who reads Karl Ove Knausgaard's My Struggle, but changing the framework of such a relationship is no easy task...

Freely adapted from the novel Box Hill by Adam Mars-Jones, Pillion (a term evoking the back seat of a motorbike) is an unabashedly raw and relatively stunning film in its meticulous depiction of the banality of highly unconventional practices. Harry Lighton overcomes the pitfalls of a daring cinematic gamble thanks to the performances of his two protagonists, but above all by succeeding in giving the whole thing a highly ironic, bittersweet tone. It's a cheeky, very British sense of humour that may prove controversial, but it allows viewers to enter an ultra-codified world and project themselves, without feeling sorry for themselves, into the sentimental torments of the very docile Colin: “Your grip is a promise, your gaze a flame, next to you I'm nothing, but I'm yours all the same”.

Pillion was produced by Element Pictures (UK/Ireland) with BBC Film (UK) and the BFI (UK). British company Cornerstone Films will handle international sales.