Her parents met on the set of “Some Kind of Wonderful,” but Zoey Deutch is about as far from the world of John Hughes as you can get in playing a morally corrupt teen in the weed-infested “Flower.” Her Erica, a high school senior with a lucrative scheme of extorting everyone from the pizza-delivery guy to her shantytown’s sheriff by freely offering a sexual act followed by blackmail, knows no bounds. There’s nothing she won’t say or do to get her way. And why not? She always gets what she wants, and what she wants most is to earn enough ill-gotten cash to bail her casino-robbing Dad out of jail. But when she crosses paths with an accused pedophile, her skanky sex games might well take a fatal turn.

Sheesh! My, haven’t we come a long way from the day when Hughes wrote wholesome — well, sort of wholesome — teen comedies like “Wonderful,” directed by Deutch’s father, Howie and starring her mother, Lea Thompson? Same goes for Max “son of The Fonz” Winkler. His direction, and the lascivious script he penned with his Independent Spirit Award-winning pal Matt Spicer (“Ingrid Goes West”), would make Richie Cunningham blush. But it also just might make him laugh, albeit nervously at all the talk — and drawings (Erica is a budding artist who can sketch from memory) — of penises our shifty heroine has known intimately.

Where “Flower” wilts is in Winkler’s inability to achieve a consistent tone, as Erica’s sordid story veers from screwball comedy to deadly serious and back, often in the zip of the pants. It also becomes painfully obvious that Erica’s progressive approach to sex as a weapon is merely a cover for what amounts to just another standard coming-of-age yarn in which tough issues — and even tougher predicaments — yield easy outcomes.

It’s a substantial letdown for the movie, but an even bigger one for Deutch (“Before I Fall”), who acts her butt off making Erica as wonderfully weird as she wants. So much of her performance generates not from the script, but from the heart. And injecting heart into a borderline sociopath like Erica — and making her likeable — is a task few other young actresses could pull off so stealthy. One minute you want to hug her; the next, brain her. And the way Deutch tosses off wry one-liners — like her goal of being accepted to DeVry — are wickedly funny.

What’s not so hilarious is the flippant manner in which Winkler and Spicer approach the sobering topic of child molestation. They practically mock it through the alleged victim, Luke (an excellently disturbed Joey Morgan), the drug-addicted, Asperger’s-like teenage son of Bob (Tim Heidecker), the nerdy man about to move in with Erica’s desperate-for-love mother, Laurie (the always reliable Kathryn Hahn). At first, Erica is repulsed — as are we — by Luke’s creepy demeanor. But when he reveals his traumatic past to her, Erica’s hard-as-ice exterior begins to melt.

To reveal more would approach spoiler territory, but believe it when I say Winkler turns credulity to the wind with a succession of increasingly ridiculous plot twists that could only occur in the mind of a lazy scriptwriter. And the way he wastes both Deutch and Adam Scott — as Erica’s troubled, bowling alley crush — borders on egregious. Still, I can’t fault Winkler’s competent, occasionally clever directing style, which leans heavily on a freewheeling approach that holds your interest. It’s also easy to admire his attempts at crushing the double standard, at one point acquitting Erica the opportunity to note that if her promiscuity were packaged in a male body, no one would bat an eyelash. And that’s what makes “Flower” so much in the now amid the #TimesUp and #MeToo movements.

Like most women, Erica knows men are stupid, don’t think with their brains and are easy marks for sexual exploitation. So, what’s wrong with her taking advantage the same way Alpha males have used and abused women for centuries? It’s outlandish, yes. It’s also strangely liberating. But as a “sex comedy,” “Flower” almost makes you long for the quaint days of “Risky Business.” Or, more to the point, the era of John Hughes, a filmmaker of integrity who knew how to empower young women, and did it without all the sleaze.

“Flower”

Cast includes Zoey Deutch, Kathryn Hahn, Tim Heidecker, Adam Scott and Joey Morgan.

(R for crude sexual content and language throughout, graphic nude drawings, some drug content, and a brief violent image.)

Grade: B-