How do you know you are growing apart as a couple?

Maybe he’s watching the football World Cup, while you’re cheering on the tennis at Queen’s. You’re vegan and he jokingly orders ‘foal’ on holiday in France. You nurture a sourdough starter but he suddenly announces he’s coeliac. You work out; he’s nurturing a beer belly from the sofa.

It sounds frivolous, doesn’t it? Inconsequential. But when your values – how you bring up your children, think about money, even what you believe is acceptable to post online – differ wildly, then there is serious trouble in store.

In recent months, public appearances and social media posts from the Duke and Duchess of Sussex have made it seem as though the couple are not only on different paths, but they inhabit different planets.

Take Harry’s appearance at the NBA finals in San Antonio last weekend. While we might have expected to see him sitting courtside with the likes of A-listers Taylor Swift, Timothee Chalamet and Kylie Jenner, Harry chose to sit eight rows back with US army veteran JP Lane. All he wants is to lay low and surround himself with the right people. Might Meghan have pushed to sit with the limelight-hugging stars if they’d gone together?

Now, I don’t want to come off all ‘Paul and Linda McCartney’. Once married, Paul insisted his wife and children came on tour because he knew the dangers of long periods apart. Of course, married couples don’t have to be joined at the hip; separate passions mean you have more to discuss and you often enjoy the time you do get together far more. And maybe Meghan couldn’t stomach yet another NBA match.

But it’s not just the basketball game from that weekend which proves my point. On the same day of the match, Harry delivered a video message about his upcoming Invictus Games in Dusseldorf for wounded, injured and sick military personnel and veterans. Harry commended Germany for ‘setting a powerful example of what it means to honour service… with dignity and enduring commitment’.

Meanwhile, on the same day Meghan was busy posting a photo dump captioned ‘Spring into Summer’. The images included her lying on the grass, nature shots, Archie playing, ‘onion cutting’ (whatever the hell that is), Lilibet’s T-shirt and a hug with her hubby. It’s a clash of the bucolic, with Meghan’s additional aim of selling stuff, juxtaposed with her husband’s desire to make a difference.

The chasm between Harry’s commitment to duty and Meghan’s obsession with building an influencer brand is hardly new. Let me walk you through how the cracks in the Sussexes’ perfect facade have started to show in the past few months.

Last November, when Meghan dragged Harry along to Kris Jenner’s birthday party, he looked undeniably uncomfortable mingling with the LA crowd. But he went along to the event, perhaps for his wife who is impressed by A-list stars, McMansions, champagne towers. Of course, he isn’t. He lived in an actual palace. His mother was the most famous woman on the planet and look where that got her! He’s sick of people bowing and scraping, he wants to be ordinary (hence those eight rows back), make a difference, leave a legacy.

But as soon as a photo of the Sussexes at the Jenner party was posted to Instagram, and people started questioning why they were out partying with celebs at the same time that the rest of the Royal Family were preparing to mark Remembrance Day in Britain, the photos were swiftly deleted. Was it because Harry couldn’t stand being seen neglecting his old royal duties?

After the party came the couple’s quasi-royal tour in Australia in April. Meghan ensured she found every opportunity for self-promotion. Perhaps unsurprisingly, considering the tour followed Netflix’s announcement that they were dropping her reality TV show With Love, Meghan in March.

While Harry spent time meeting veterans, his wife, visiting the site of the massacre on Bondi Beach, was simultaneously promoting her outfits on One Off, a company that identifies where celebs’ clothes are from. She’s even a minority shareholder in the business. With Harry busy trying to act like a working royal, Meghan was seeking a slice of profit in one hand while shaking the hands of the victims’ families with the other.

Much worse, though, was Meghan’s Instagram post last month of their daughter, Lili, then aged four, crouched in her walk-in wardrobe captioned ‘Mama’s little helper’. It did make me wonder whether Meghan was about to launch a fashion line, given the sales of her fruit spread are reportedly so dire, the unsold jars are soon to sail past their sell-by date.

At first glance, it seemed like any other post, but the timing was odd. She shared the photo on the eve of an appearance in Geneva where she delivered an anti-social media speech at an event outside the World Health Organisation about online harms to teens, unveiling the Lost Screen Memorial, a moving tribute to children who have died as a consequence of social media harm.

So why was she posting photos of her young daughter on social media on the eve of an address warning against the dangers of such platforms?

Surely the irony can’t have been lost on Harry. You can imagine him reeling at his wife’s tone-deaf approach, particularly because his preference for privacy is no secret.

Harry is due in Britain next month to promote the 2027 Invictus Games in Birmingham.

It’s doubtful Meghan and their children, Archie, seven, and Lili, now five, will accompany him. I’m sure Catherine yawns at the prospect of joining William to gawp at yet another tedious flypast, but she does it. She dons a hat and puts him first. I doubt very much Meghan wants to tag along: it’s all too provincial.

Meghan has had to be a grifter to make her way in Hollywood, whereas Harry never had to try. First she found success as an actor. But now she’s living a life akin to a Made in Chelsea or Real Housewives star – not an offshoot of the Royal Family – promoting her clothes, launching a lifestyle brand and constantly sharing snaps of a domestic idyll on Instagram.

As Harry wrote in his notorious memoir Spare, for him fame is nothing more than ‘a joke’ or ‘fancy captivity’. He’s more interested in doing good. But for Meghan, the perfect life is all about branding and staying relevant. So can the Sussexes overcome their starkly different approaches to publicity?