There are roles that mark a turning point in an actor’s career—and then there’s Ponyboi, where Dylan O’Brien delivers a nude, post-coital rap about “isosceles-ing the babysitter” after geometry class.

It’s not the kind of sentence anyone expected to write in 2025, but O’Brien isn’t playing by the old Hollywood playbook anymore. Known for teen dramas and action-packed franchises (Teen Wolf, The Maze Runner), the actor dives headfirst—and bare-assed—into something far stranger, riskier, and more meaningful in Ponyboi, the intersex-led crime drama by writer-director-actor River Gallo.

“It was Dylan’s ass debut,” Gallo said with a laugh in an interview with Entertainment Weekly. It’s technically true. O’Brien gets up after an intimate scene early in the film, fully nude, and launches into a self-penned freestyle that’s… well, hard to forget. Between lines about “white hoes” and cereal-box masculinity, the performance teeters on the edge of absurd, cringey, and oddly sincere—exactly where it’s meant to land.

That moment alone is enough to raise eyebrows, but it’s the intent behind it that makes it memorable. O’Brien didn’t just say yes to the nudity—he pushed for it.

“I wanted to do it naked, too. That was another thing I insisted on,” he explained. “We’re laying there naked, it would make sense that I’d get up and I’m rapping it naked in front of you.”

The visual—a bare O’Brien, delivering embarrassingly earnest bars while River Gallo’s Ponyboi listens from bed—is both hilarious and weirdly intimate. Even the shot composition, with O’Brien’s rear in the foreground and Gallo’s reaction behind him, was a deliberate choice. “My ass in the foreground, I thought would be a funny shot,” he said.

Funny, yes. But also oddly brave.

In lesser hands, Vinnie might be nothing more than a white-boy caricature with delusions of musical grandeur. But O’Brien threads something rare into his performance: a kind of tragic tenderness. Vinnie isn’t just comic relief—he’s a lost boy with ambition, vulnerability, and no roadmap. And for a film like Ponyboi, which is all about visibility and the power of being seen, his naked honesty—literal and emotional—feels right at home.

That honesty is at the heart of the film. Ponyboi marks the first time an openly intersex person—Gallo—has written and starred in a feature-length film about an intersex character. Set against a stylized, early-2000s New Jersey backdrop, the film blends crime noir, queer fantasy, and raw autobiography to tell the story of a sex worker dreaming of escape and self-definition.

“It’s been challenging,” Gallo said of carrying that cultural weight. “People have said, ‘You’re blazing trails, you’re the first,’ but it’s sort of a burden to take on a little bit, because I can’t speak for everybody… I can only be as specific as I can about my own experience, with the hope that this will inspire new artists and filmmakers to carry the torch.”

Gallo’s performance is striking, magnetic, and painfully real. But part of what makes Ponyboi hit so hard is how deeply the cast around them commits to the vision—including O’Brien, who brings a kind of chaotic authenticity to Vinnie that’s rare to see from actors with leading-man resumes.

And yes, he wrote that bizarre rap himself.

“Literally in the script I wrote, ‘Bad rap goes here,’” Gallo said. O’Brien took that prompt seriously, crafting the lyrics on his own in the days leading up to the shoot. “They trusted me to the point where I didn’t even show it to them until the morning that we were shooting it,” he said. “If anything, the note was like, ‘It might be too good. He’s still kind of a loser, remember?’”

It’s that willingness to lean into awkwardness—not just for laughs, but for emotional truth—that makes O’Brien’s turn in Ponyboi so unexpectedly affecting. This isn’t about shock value. It’s about showing up, fully and unflinchingly, in service of a story that hasn’t been told before.

So yes, Ponyboi may go down in history as the film where Dylan O’Brien rapped naked. But more importantly, it’s a film where he said yes—to queer storytelling, to discomfort, to being ridiculous and real at the same time.

And honestly? That might be the boldest move of all.

Ponyboi is now playing in theaters. Bring a friend. Maybe warn them first.