The cover of Tom Perrotta’s satiric new novel, “Mrs. Fletcher,” depicts an attractive brunette tucked in bed, her face illuminated by the glow of a smartphone. The woman in question is the eponymous Mrs. Fletcher, a latter-day Mrs. Robinson recast in a more complicated world.

Eve Fletcher is a 46-year-old divorcee and single mother who lives at the intersection of suburbia and angst. Both Eve and her son, Brendan, are on the verge of a relaunch – Brendan into the chaos of freshman year at college; Eve into the uncertainty of the empty nest.

While her day job as director of the local senior center provides bland respectability, Eve yearns for something more. And out of the blue, it arrives. One day she receives an anonymous text that reads, “U r my MILF!” Unnerved by this message, she can’t quite shake its intrusion. So begins her darkly comic descent into the world of so-called MILF porn, where she discovers a website that hosts a seemingly endless array of amateur porn videos whose participants are middle-age folks like herself.

“There was no doubt about it – milfateria.com was part of that ‘unregulated cesspool’ the assistant DA had warned about so many years ago,” Perrotta writes. “Eve was regularly shocked and frequently disgusted by what she found there. She disapproved of the site – she would have been horrified if she’d ever found anything like it on her son’s computer – and sincerely wished it didn’t exist. But she couldn’t stop looking at it.”

Eve finds herself debating whether hers is an addiction or a habit – more like heroin, on the one hand, or coffee, on the other. It’s part of the slippery slope that Perrotta conveys so effectively, as Eve takes to blurring boundaries and crossing lines that would never have occurred in her earlier life.

Her steady diet of porn leads to a banquet of blunders – crossed signals with a subordinate at work, hooking up with an old classmate of her son’s, and other awkward indiscretions. And with it, a sense of emptiness and wasted time sneaks up on her more than occasionally.

Meanwhile, Brendan’s first semester at college is a muddle of booze and sex, and attempts to score more of each. He’s a mother’s worst nightmare of cluelessness and privilege, so that when he sees his image looming large on a college art show’s wall of shame, readers may cheer his comeuppance.

Perrotta, who’s known for his novels “Election” and “The Leftovers,” draws heavily from the news of the day, including such hot-button issues as body shaming, consent and hook-up culture; transgender identity, entitlement and bullying. His assault on political correctness is scathing and relentless, a running theme throughout the book.

In the end, Perrotta has written dual coming-of-age stories. In alternating chapters, we witness a mother and son at different stages of life, trying on new selves. Eve – smart, obsessed, lonely, ambivalent – has credibility and introspection on her side. She actually reinvents herself along the way, gathering new friends and adventures, albeit some more risqué than others.

But Brendan’s bro-dude-frat boy persona is so over the top that his growing self-awareness seems, at times, less convincing. As the book’s title suggests, however, Eve is the star of this show. Her inner monologue is the very meaning of vacillation with all its droll and dire missteps. Her shenanigans make for a rich stew of desire and conflict, and their inevitable consequences.

In the closing pages, Perrotta throws in a surprise ending to this racy romp, a final wink to the reader.

Joan Silverman writes op-eds, essays and book reviews. Her work has appeared in The Christian Science Monitor, Chicago Tribune and Dallas Morning News.