The PDA between men and the insouciant way they are enacted is new to Hollywood. Not to mention elsewhere, where platonic male intimacy is unchartered territory on the long road of guys being OK with their feelings about each other, or just our feelings full stop.

We live in a world where putting a “x” at the end of correspondence with another man feels weird. I struggle to think of any guys who are comfortable enough to advance beyond carefully choreographed hugging with their friends. When I went in search of some who might, I thought of Mr Jack Remmington, figuring that as a high-profile presenter and influencer he would be sufficiently celebrity adjacent to encounter this new way of being. But it is in ordinary settings he has experienced platonic male intimacy.

“Whenever I greet my barber or a uni friend, they peck me on the lips,” Remmington says. “They both introduced it independently of one another one day and we’ve kind of rolled with it.”

It feels important to mention that all three men here are gay. Our reticence to express ourselves in an intimate way with other men is tied up with a lifetime of being told that anything man-on-man is a very bad thing. Gay men like Remmington will have had to reckon with this in their romantic lives already. Might that make it easier to slip into platonic intimacies between male friends?

“I’m always slightly taken aback by it, but not in an uncomfortable way,” Remmington says. “It just has never become something I’m super used to, probably due to social conditioning of how male friendships work.”

So, how about a straight man? I knew my friend Mr Dan Hudson had kissed a guy – his work colleague, Mr James Barr, for a magazine cover – so I wondered if that was their usual mode of being with other. “I’m not sure who conceived that idea for the cover, but it wasn’t me,” says Hudson, who is straight and co-hosts a podcast, A Gay And A Non-Gay with Barr, who is gay. “We certainly don’t do that to greet each other, more like a firm handshake or a hug if we’ve done a particularly good episode.”

Barr, meanwhile, thinks that any efforts to break down barriers for men to express themselves can only be good. But he worries about queerbaiting – when straight celebrities imply queerness for, say, social media likes. “When it’s James Corden doing a ‘bit’ by making out with Harry Styles [in Carpool Karaoke], I find it offensive,” he says.

And LGBTQ+ folk have good reason to be suspicious of a trend, given Hollywood’s track record on representation. Until relatively recently, a big-screen kiss between men was played for laughs. But modern leading men appear to strike a different, sincerely meant note. Mr Andrew Garfield set an example at the 2017 Golden Globes when he kissed his friend Mr Ryan Reynolds for a laugh, but also because he “just wanted Ryan to know I loved him no matter whether he won or lost.”

The A-list trend reflects wider progress. Changing social attitudes towards homosexuality have eased conditions for men of all sexualities to show affection to each other. A UK study found that 89 per cent of college guys surveyed had locked lips with another man in a non-sexual fashion while an American study found that 40 per cent of straight college men had kissed on the cheeks. These are small surveys in the relatively safe, experimental spaces of college campuses, but they do support a sense that men are open to more than a firm handshake.

“Men want to be able to be themselves,” says Dr Jesse Steinfeldt, a sports psychologist who specialises in men and masculinity. “They want to be able to express themselves. Men don’t want to be constrained by invisible and artificial rules about how they should act.”

Steinfeldt, a professor at Indiana University Bloomington, studies men in a setting where affection between each other thrives. The sports pitch is the original safe space for male-on-male fondness, a place where hugs, kisses, or a pat on the bum for scoring are as common as a deliberate dive in the 10-yard box. But there is a dichotomy in play, Steinfeldt says.

“In football, men are afforded the opportunity to not only verbalise their affection like, ‘my teammates are my brothers,’ or, ‘I love my brothers,’ but to also demonstrate their affection physically,” he says. “In this space where these visual demonstrations of man-on-man affection exist, there paradoxically exists a homophobic undertone that prevents men from acknowledging that these shows of affection are, in fact, affection.”

Even if we were to disentangle ourselves from deep-seated expectations around masculinity, difficulties remain that even actors can’t make look straightforward. Kissing, as any rom-com aficionado will tell you, is never easy to execute successfully. Just watch how Murphy swerved Downey Jr’s attempt at a kiss on the lips. The lesson? Signpost your intentions clearly.

“You don’t need to get the lips straight on there,” advises Mr Daniel Senning, a coach at Emily Post Etiquette. “Be prepared that the person you are interacting with might or might not be expecting it. Indicate or gesture, but don’t impose it on someone, so it can be accepted or declined.”

Kissing is one of our most personal expressions, and dependent on many other factors like comfort levels, cultural differences and consent, irrespective of the gender of your intended. Senning, who is American, recalls that on his wedding day, his family wanted to see a kiss, which for his wife’s side, a largely Indian contingent, would have been inappropriate. “In Indian culture, public kissing is not appropriate,” he says. “I thought to myself that for half of this crowd, that’s a weird thing for us to do right now.”

Hugging might be the safe place to land for many, for now. “Honestly I can’t imagine ever doing it [platonic kissing] and I wouldn’t want anyone to do it to me,” says the podcaster Hudson. “I’d think it was a huge invasion of my personal space. I wouldn’t do it to a woman either; I’d leave it at a hug.”

Steinfeldt, meanwhile, reserves kissing for his close family. Could he ever see himself moving in for a platonic kiss? “Perhaps, but I do think there are stigmas around masculinity and being perceived as less than heterosexual that keep kissing from being added to the repertoire of acceptable man-on-man affectionate displays. Someday, maybe?”

Now that would call for a celebratory kiss.