Doin’ It revolves around surely the most literal interpretation imaginable of the old saying “those who can, do; those who can’t, teach.” Lilly Singh stars as Maya, who stumbles almost by accident into a job teaching sex ed, despite still being a virgin. As she schools her kids on everything from consent to gender identity to orgasms, Maya sets out to unlearn the shame that she herself internalized at that age — and maybe even to get laid for the first time.

Good intentions practically drip off the premise, which makes a convincing case for dismantling the fear and ignorance around adolescent sex ed. And Doin’ It puts its money where its mouth is — its jokes eschew pearl-clutching or coyness in favor of in-your-face crassness. But the comedy never quite settles into a comfortable rhythm, and eventually backs itself into a corner so far away from any recognizable reality that it threatens to undermine the very message it wants to send.

Doin’ It‘s NSFW sensibility is front and center from the very first scene, in which a 15-year-old Maya has semen squirted in her face twice in five minutes by a friend who cannot control his excitement at getting to see her boobs. Her curiosity turns to humiliation, however, when a mishap involving a stage curtain reveals the moment to an entire auditorium of students and parents. Horrified, Maya’s mother (Sonia Dhillon Tully’s Veena) sends her packing to India, where her urges are further disciplined out of her: When she’s caught playing MASH in class, she’s made to stand outside in the heat “until all your dirty thoughts melt away.” By the time Maya returns to the States as a 30something software engineer shilling for a teen-oriented app, she’s hardly more experienced than she was as a teen. But in an effort to research her target demo, she picks up the teaching job and simultaneously tries to catch up on all the adolescent experiences she missed way back then.

Doin’ It is at its brightest in Maya’s personal journey of self-liberation, which yields one comically mortifying situation after another. While the actual gags are hit or miss (running bits frequently overstay their welcome, and too many jokes are built on formats so hoary we can see the punchline coming from three miles away), the frankness with which they’re presented is refreshing: Maya may blush at seeing her first vibrator, but her movie has no qualms about showing us that same vibrator messy with recent use. Its playful attitude toward sex is most fully embodied by Sabrina Jalees as Maya’s BFF Jess, a scene-stealer whether she’s fingerbanging papayas at the grocery store or crowing about how her DJ girlfriend “remixes my pussy like fucking Tiësto.”

Meanwhile, the film extends sincere empathy toward Maya’s struggle to internalize in private the sex-positive values she espouses in public. “I’m confident with everything else but when it comes to this stuff, it’s like I’m broken,” she cries after a date with a cute fellow teacher (Trevor Salter) ends with her cruelly projecting her own fears about being “weak” and “prudish” onto him.

Her arc is neatly complemented by her mother’s. When Veena insists she couldn’t possibly date because she’s not that kind of woman — even while she laps up storylines about middle-aged romance on Never Have I Ever — we see how repression gets handed down the generations. In that light, Maya’s determination to break the cycle with her own students feels all the more noble.

The problem is that Doin’ It‘s idea of Maya’s work is so underbaked, it’s practically raw. “Maybe I have an opportunity here,” she muses when Jess mentions that half the schools in the state don’t even have sex ed, and that’s all it takes for Maya to decide to throw out the abstinence-only curriculum mandated by the district. On her first day, she’s so green she doesn’t know the difference between an IUD and a UTI. Seemingly overnight, she’s playing Betty Dodson videos and breaking down the best woman-on-top sex positions without so much as batting an eye. In doing so, she’s framed as an inspirational teacher in the Dead Poets Society mold, meeting her students at their own level in defiance of the oppressive standards that define the world around them. But the script, by Singh, director Sara Zandieh and Neel Patel, is never very clear about the challenges or the stakes she faces.

The opposition to her teachings is strangely toothless — none of the other parents or teachers even notice how drastically she’s strayed from the lesson plan for weeks, and once they do, the ensuing pushback plays out with more confusion than venom. It’s outside the scope of any one movie, let alone a lighthearted comedy like this one, to fix the state of sex ed in America. But as high-school students in the real world deal with book bans, limited contraception access and parental notification bills, Doin’ It‘s reluctance to touch on those weightier topics has the effect of minimizing the problem. In this fantasy, all you need to transform an entire generation’s relationship with sex is for a single teacher to decide that she wants to do it.

“We need a sexual revolution, and it starts in this place, today,” Maya declares in a dramatic speech, and she’s not wrong — her own storyline in Doin’ It serves as a warning of how the damage wrought by shame can take years or decades or entire lifetimes to move past. But if today’s youth indeed deserve honesty, the film might start by being a bit more candid about what the sex-positivity movement is really up against.