In hell, we’ll hear echoes of all the well-meaning criticism we gave our kids: every perfectly reasonable judgment on that T-shirt, that friend, that music, that mess, that earring, that homework!

But our intentions were good, right?

In David Nicholls’s new novel, “Us”longlisted for this year’s Man Booker Prize — a father discovers just how much those intentions are worth to his hectored teenage son. This is the sort of witty book that guys should read the moment their partners say, “I’m pregnant!”

Or maybe earlier.

After 20 years of marriage, Douglas Petersen wakes up one night to hear his wife tell him, “Our marriage has run its course. . . . I want to leave you.”

”Us” by David Nicholls. (Harper)

To Douglas’s surprise, his once attractive practicality has grown pinched and cold over the course of a long marriage. But in this irresistible novel, we see him from the conflicted inside: “I loved my wife to a degree that I found impossible to express, and so rarely did,” he tells us. “I am 54 years old . . . and have one son, Albie, nicknamed ‘Egg,’ to whom I am devoted but who sometimes regards me with a pure and concentrated disdain, filling me with so much sadness and regret that I can barely speak.”

More often, though, the trouble is that Douglas does speak. There’s nothing about Albie that doesn’t frustrate him. Tell me you haven’t muttered this under your breath: “He refuses to wear a coat, an absurd affectation, as if coats were somehow ‘square’ or un-cool, as if there were something ‘hip’ about hypothermia. What is he rebelling against? Warmth? Comfort?” And then there’s the boy’s room, “an immense Petri dish of furry toast crusts and lager tins and unthinkable socks that will one day have to be sealed off in concrete like Chernobyl.” Douglas presents that most common tragedy of parenting: He would do anything for his child — except tolerate a little teenage attitude. “I disapproved because I cared,” he claims. “Why wasn’t that apparent?”

Douglas tells us at the start, “This is a love story,” but it’s often a comedy and sometimes a tragedy. Trained as a scientist, Douglas knows everything about biology but little about life. Over the years, he’s failed to understand just how alienated from him his wife and son have become. Determined to improve, he does what any well-organized scientist would do: He draws up a list. No. 3 states, “It is not necessary to be seen to be right about everything, even when that is the case.” Ominously, No. 8 advises, “Maintain a sense of fun and spontaneity.”

In fact, Nicholls’s entire novel comes to us as a long list of short, numbered sections — from one to 180. That super-organized structure, though, is no match for the messiness of family life. As any parent knows, there’s no list a teenager can’t scramble.

Like Emma Straub’s “The Vacationers,” which came out earlier this year, “Us” is the story of a fractured family going on a trip: “the last summer holiday we’ll have together.” Despite her divorce plans, Douglas’s wife imagines a Grand Tour to prepare their college-bound son for “the adult world, like in the 18th century.” The young man, of course, would rather take the money and go off drinking with his buddies. To Douglas, who knows his marriage is over, this expensive expedition sounds like “a funeral cortege, backpacking through Italy.”

Nicholls is a delightfully funny writer with a huge audience in England — his most recent novel, “One Day,” sold more than two million copies and was made into a film — and this over-planned vacation makes ripe material for comedy. If he were only a prig, Douglas would be an unbearable narrator, but he has a lovable, self-deprecating sense of humor, and he’s as frustrated as anyone else with his inability to relax, to accept, to let it go. “I reeked of disapproval,” he confesses. And to all the usual pressures that travel is heir to, Douglas adds his determination to turn the Grand Tour into the Grand Cure: a summer so packed with good cheer that his wife will fall back in love with him and his son will realize just what a swell dad he has.

If you’ve ever left the house, you know that itinerary goes off the rails almost immediately. “I did my best,” Douglas says, “but my manner was queasy and self-conscious, like a children’s entertainer who knows his act is failing.” At their first stop in Paris, they check into a room “that was clearly the result of a wager to determine the smallest space into which a double mattress can fit. Brassy and vulgar, the bed frame must have been assembled inside like a ship in a bottle. On closer examination, it also seemed our room was a repository for all of Europe’s spare pubic hair.” The next room, which seemed perfectly lovely online, looks like a top-of-the-line bordello in a sex dungeon.

Almost immediately, Douglas’s efforts to win over his 17-year-old son are thwarted by the arrival of a sexy accordionist from New Zealand who majored in ventriloquism. Albie is smitten by this obnoxious young woman — who wouldn’t be? On the worst nights, Douglas and his wife lie in bed trying to block out the sounds of “Purple Rain” while their son and his new girlfriend carry on next door.

Yes, some of this has the madcap predictability of a rom-com available on DVD three weeks after its theatrical release. Douglas never tasted a hot chili sauce he won’t accidentally rub into his eye. Showing off his strong swimming at the beach, he’s surrounded by jellyfish (he imagines his corpse washing up on shore in an alarmingly tight bathing suit). But I found myself laughing — sometimes out loud on the Metro — through many of these antics. After a long season of novels focused on rape, torture and child abuse, “Us” felt like a welcome break.

The real artistry of this book stems from its clever structure. Even as Douglas’s doomed little family trudges around Europe, the narrative constantly shifts back 25 years to the beginning of his relationship with the attractive young artist who became his wife. She and her bohemian friends are so cool, and he’s so square. “I danced,” he confesses, “like someone wrestling with a bout of diarrhoea, clenched and anxious.” He’s overwhelmed by their differences but determined to impress her, to change, to do whatever he must to attract her. Before her first visit, he frantically redecorates — new postcards, new throw rugs, new underwear: “If she ever set foot in my flat, she would mistake me for someone else entirely; a bachelor of quiet good taste and simple needs, self-contained and self-assured, a man of the world who owned van Gogh prints and cushions and smelt of trees.”

The story of how that excited young man became the panicked middle-aged husband desperate to save his family is the real voyage of this novel. For all its bad meals, lumpy mattresses and cramped train seats, “Us” evolves into a poignant consideration of how a marriage ages, how parents mess up and what survives despite all those challenges.

Charles is the editor of Book World. His reviews run every Wednesday in Style. You can follow him on Twitter @RonCharles.

Us

By David Nicholls

Harper. 396 pp. $26.99