"Are there any paedophiles here today?" A row of 13 year-old girls in gym kit stare out at us, innocent and accusing. Each is, as Britney put it, not a girl, not yet a woman – bodies in the state of becoming. They are what they are, adolescents, but the way we see them – perhaps particularly in this country, squeamish as it has become – slips and slides. They are both children and not.

The Hamilton of Lies Pauwels' title is not Alexander, but David: the British photographer whose teenage nudes have caused such controversy over the years – defended as innocent; attacked as indecent. The distinction, Pauwels argues, is down to us – the beholders – and what we project.

From the start, Pauwels invites us – no, forces us – to see these girls sexually. They scream the shrill squeals of Beatlemania, losing their heads in hormonal hysteria, then flash their knickers at us mischievously. Dolled up in candy-coloured wigs, the girls cock their heads to one side and bite their lips coquettishly. They meander dreamily around the stage, flowers in their hair, dressed all in white – postergirls breezing through grassy fields. It takes a touch of lipstick to tip them into womanhood.

It is a difficult, difficult watch – perhaps all the more so as a straight, young man. We've been conditioned to see these gestures as sexual, but there's no escaping their childishness and their vulnerability here. The critique is not of us individually, but of society as a patriarchal whole: not how children are sexualised, but how grown women are infantilised. It is as fierce a feminist cri de coeur as I've ever seen on a stage.

Pauwels keeps us attuned to the aesthetics. Marble columns and an idyllic oil landscape suggest a certain classicism. Onstage with the girls, there's a male bodybuilder; the image of ideal masculinity. What, then, is the feminine equivalent? The young beauty? The nymph? Pale skin. Rosy cheeks. Silence. Deferral. The girls go by names like Melody, Eternity and Patience, and line up in swimsuits like beauty queens. One presence disrupts the whole: a young girl, Queen, who has cerebral palsy. Why is she not that ideal?

Sometimes, the girls seem outright scary. One moment, they're Red Riding Hoods with their faces concealed; the next, fitting, demonic figures like the girl from The Ring. What is it about young women that we find so alarming? They're marshalled with a whistle and later leashed on all fours – trained into obedience, maybe even obsolescence. There's no escaping what these girls might become – and, indeed, what they might not.

Because The Hamilton Complex is not just of adolescence, but about it as well and Pauwels catches all its turbulence, its terrors and its joys. Dancing with the bodybuilder, they seem both at risk and protected. Every image is just as complex. Childish bodies sprout pregnant bellies. Schoolgirls overpower a grown man.

At the same time – just to add to its complexity – this is a metaphor for a world in flux and for history. A piece that starts with jubilant screams ends with limp bodies dragged into a heap. Chloe Lamford's utopian stage – rainbow overhead, plastic unicorn peeping out behind a curtain – turns into a warzone. Ours, perhaps, is a world that has lost its innocence.

In short, it's stunning. Funny. Uneasy. Alarming. Affirming. Disarming and difficult. A piece that stands firm and holds our gaze. Theatre that treats us like grown-ups. I could go on, but you should just go.

The Hamilton Complex runs at the Unicorn Theatre until 2 July and at the Birmingham REP on 5 and 6 July.