Grade: 3.0/5.0

The American sex comedy died as it lived: conforming to the formula of an adolescent man’s culturally deemed “rite of passage,” following reprehensible juveniles who will do anything or anyone to prove their masculinity. A breeding ground for lame gross-out humor, regressive moralizing and eager bouts of homophobia, it was seemingly for the best for the genre to sink away into antiquity.

Arriving years post-mortem is “Blockers,” a new comedy directed by “Pitch Perfect” screenwriter Kay Cannon, which finds retributive value in the defunct model. Recontextualizing the nastier attitudes of the “American Pie” series of yore, the film offers a compassionate — albeit sanitized — spin on the “first time” comedy.

At first glance, the film tells an age-old adolescent tale: Three lifelong friends make a pact to lose their respective virginities on prom night. Juxtaposing this narrative is that of three of their concerned parents, who, after snooping through their daughters’ group text and coming to terms with what eggplant emojis connote, pursue their children with the determination of Vin Diesel in an attempt to stop the copulation from occurring.

“Blockers” splits itself between these two narratives, finding plenty of laughs in both. The parents constitute an unlikely, but surprisingly balanced, comic trio. Leslie Mann, a seasoned veteran of the self-imposed parental nightmare comedy, is the clear standout. As the single mother Lisa, Mann gives a performance that’s at once farcical and grounded. The mental backflips made to justify refuting her daughter’s autonomy are amusing in their ludicrous logic, but Mann hones in on the insecurities that inspire such unthinking protectiveness.

Meanwhile, John Cena effectively weaponizes his absurd physicality in an effective portrayal of helicopter parenting. Ike Barinholtz, a longtime bench player, finally receives a larger role to showcase his self-loathing in the role of an absentee father.

The comic chemistry between the parents amply carries “Blockers” from beginning to end. Thus, it’s hard to put too much blame on the film for giving them the spotlight, unable to appreciate the spectacularly realized teenage performances. While the film recognizes the comic potential of the daughters’ debauched night out, it fails to actualize the emotional crux of its absurd tale, which lies in their self-discovery and kinship.

The teenagers are more sharply defined than their parents. A longtime high school sweetheart (Kathryn Newton), an enthusiastic party animal (Geraldine Viswanathan) and a closeted gay student (Gideon Adlon) each share a similar goal for the night but all possess their own emotional investments and insecurities. What sells their scenes together is the organic chemistry the three actresses share, behaving as friends with a long history instead of comedians simply riffing off each other — something the parents never quite transcend.

It comes as a surprise that these newcomers are able to maintain the film’s fizz on their own, while the adults rely on absurd situational comedy to achieve laughs. Still, the joke of having parents navigate a gauntlet of youth culture’s dirtiest streaks — including butt-chugging — in order to enact Puritan instincts is amply flexible. Though the focus is imbalanced between the two groups, the film manages to mine fresh laughs from its well-trodden premise.

It’s once these two stories intersect that the film stumbles, substituting rote progressive attitudes for a credible conclusion. When the parents finally catch up to their children, they rightfully realize the errors in their ways. However, the teenagers’ storyline is demoted to fodder for the A-list actors. The contrived nature of the parents’ collective moral quandary is laid bare as the daughters pat them on their backs, forgiving their helicopter instincts while forgetting their own plans for the night.

After deriving much of its humor from the obviously wrong-headed impulses of the parents’ mission, the film largely renders itself benign through the unnecessary explanation of that joke. Though the didactic home stretch comes from the best intentions, it robs the film’s true protagonists of a better, raunchier comic showcase. “Blockers” is hardly an uninspired comedy, but it overcompensates for its genre’s moral deficiencies with persistent sex positivity while sidelining the sex itself  — failing to recognize the hypocrisy therein.

“Blockers” opens today at the UA Berkeley 7.