Blockers starts strong and ends with a bit of a thud. As a female-first teen comedy, it feels like it might break new ground; then it reverts to the gags and goofs you’d expect from an R-rated jokefest. What keeps it from falling apart? A cast that's led by three unknown young women, a 16-time WWE champion, a veteran actress best known for her husband’s movies, and that guy from MADtv and Suicide Squad.

Lisa (Leslie Mann), Mitchell (John Cena) and Hunter (Ike Barinholtz) are cordial-at-best parents who meet up to send their kids off to prom. When they snoop on a text chain and discover that Julie (Kathryn Newton), Kayla (Geraldine Viswanathan) and Sam (Gideon Adlon) have made a sex pact for the night, they embark on a zany adventure to find and stop their presumably horny teens.

In a pleasant twist, the parents have—mostly—underrated their kids’ decision-making abilities. Director Kay Cannon and a cadre of screenwriters make it clear that the trio’s missteps stem from genuine uncertainty rather than youth. They don’t know exactly what they want, but the choices they make are clear-headed and appropriate. It’s refreshing to see a movie where teens, especially teen girls, aren’t flailing about with no idea what they’re doing.

It helps that all three young actresses embrace their characters and make Blockers more than just “female Superbad.” Viswanathan is the scene-stealer as a tomboy who can get rowdy and overtly sexual; Newton exudes enough confidence that her sparring with Mann feels like thought-out dissension—plus the usual mother-daughter tension—as opposed to childish rebellion. Adlon doesn’t get much to work with, and the reveal that she’s struggling with her sexuality isn’t artfully done, but she also doesn’t make Sam into a caricature. She’s the quiet one, and confused; that’s plenty.

And, in a pleasant surprise, the parents are just as good. We know how terrific Mann can be, from Big Daddy to her work with husband Judd Apatow, but Cena is still largely considered a pro-wrestling meathead who fell into success via Trainwreck. Well, not anymore; he gets some of the best lines, and he knocks them out of the park. And Barinholtz, who is introduced as a sort of “cool idiot” combo of all the Hangover guys, reveals a little more depth as we go and even tackles the movie’s most emotional moment with aplomb.

Unfortunately, the antics do get absurd at around the halfway point. There’s a little nude Gary Cole, some butt-chugging, and a few other moments that are smile-inducing but feel forced. At the same time, the movie’s optimistic, progressive themes—“It’s OK to be gay!” “It’s OK to have sex!”—find themselves bulldozed by lazy writing: Mitchell bashes his daughter’s date into the wall to force an unearned heartfelt conversation about growing up, Sam’s sexuality takes a back seat to jokes about her date Chad (an admittedly wonderful Jimmy Bellinger). It’s all decent enough; it just feels like standard, shoehorned-in fare that doesn’t match the script’s early momentum.

But Blockers isn’t charming because of its liberal leanings, or because of its focus on young women. It’s charming because Cena is a force, because Mann does “nervous mother” better than any comedic actress working today, because Barinholtz rises above his lazy character, and because Newton, Adlon, and especially Viswanathan all avoid teenage-girl tropes. When the script falters, the cast keeps this comedy afloat. Good luck to anyone who calls Big Match John a meathead again.