Outlaw King, David Mackenzie’s historical epic following Robert the Bruce’s bloody journey from servile nobleman to king of Scots during the first war of Scottish independence, has plenty of talking points. There’s its bravura opening for one, an unbroken eight-minute ballet introducing us to the major players and murky politics of early 14th-century Scotland. There are also the full-blooded performances from the cast, which includes Chris Pine, Aaron Taylor-Johnson and Florence Pugh. The Scottish scenery isn’t bad either. But one newcomer grabbed all the headlines when the film opened the Toronto film festival: Chris Pine’s penis.

“Pine’s penis dazzles,” exclaimed Vulture, with its article going on to give a blow-by-blow account of the scene in which Robert takes an alfresco bath in a picturesque Scottish loch. Vanity Fair, meanwhile, declared Pine’s “anatomy the belle of the ball in Toronto”. That’s not to mention the dozens of similarly breathless tweets celebrating Pine’s peen. Who needs Mr Skin when we have professional film journalists?

It’s easy to understand why everyone got so flustered. A-list male actors aren’t exactly known for dropping their trousers on camera willy-nilly. Having now seen the scene everyone got so hot and bothered about, however, it’s harder to see what all the fuss was about. Robert’s impromptu dip is shown in tasteful wide shot and last less than a second; there’s barely enough material to create a saucy gif.

Perez Hilton (@PerezHilton) IT'S CHRIS PINE'S PENIS, Y'ALL! https://t.co/KqJzhnMLA1

The person most confused about the reaction is Pine himself. “People were giggling about my penis as if they were schoolschildren,” lamented the 38-year-old actor when I spoke to him at London film festival last week. “I think it’s maybe the dying embers of this Calvinistic idea that self-flagellating and shame and anger and violence is all good and yet sex and intimacy, making love is bad. And that manifests in us all giggling about a penis – it’s so stupid.”

Those caught unawares by Pine’s display can’t be familiar with the work of David Mackenzie, who has plenty of form when it comes to convincing actors to take their kit off. Jamie Bell (Hallam Foe), Ashton Kutcher (Spread), Jack O’Connell (Starred Up) and Ewan McGregor (Young Adam, Perfect Sense) have all appeared in various states of undress in his films – although in the case of McGregor, we’re sure Mackenzie didn’t have to do much convincing. His fellow Scotsman is famously one of the few A-listers who actively welcomes the opportunity to be nude on screen. McGregor has claimed his urge to free willy is an altruistic one. “Women are always expected to be naked in films, but I like to try and do it so they don’t have to,” he said on a chatshow back in 2009. “It’s a feminist thing.”

Facebook Twitter Pinterest The undisputed king of full-frontal nudity … Richard Gere in American Gigolo, 1980. Photograph: Courtesy Everett Collection / Re

Pine seems to share McGregor’s sentiments about Hollywood’s hypocrisy. “Florence [Pugh, his Outlaw King co-star] shows her breasts and her body and no one’s talking about it,” says Pine. “Is that because she’s expected to do that as a woman, and I, as a man, am not? And why am I not expected to do that? Because it shows vulnerability or a weakness? I just don’t know.”

Is this overreaction to a glimpse of Pine’s penis the reason so many young actors are squeamish about getting naked for their art? Speaking in these pages back in March, James Ivory was irate that nude scenes in his Call Me By Your Name screenplay were altered to conform with Armie Hammer and Timothée Chalamet’s no-nudity contracts. We can understand Hammer and Chalamet’s trepidation. Just imagine, for example, if one of them were a grower and not a shower? Or, God forbid, their junk turned out to be a bit funny looking? The body shaming would be relentless.

More power, then, to the A-listers who whip it out anyway. Props should go to Oliver Reed and Alan Bates, the actors who got the balls rolling in 1969 with their gratuitous nude wrestling in front of a roaring fire in Women in Love. A slightly gone-to-seed Reed was still getting his kit off 17 years later, frolicking on a desert island in Nicolas Roeg’s Castaway, but the undisputed king of unabashed full-frontal nudity in the 80s was Richard Gere: a nonchalant approach to nudity was the perfect stance for the cocky but sensitive studs he played in films such as American Gigolo, An Officer and a Gentleman and Breathless.

By contrast, Harvey Keitel’s full-frontal antics in Bad Lieutenant and The Piano were all part of his Stella Adler intensity. Tom Hardy is not of the method school, but he’s got a similar go-for-broke attitude and utter lack of vanity when it comes to his naked body in the likes of Bronson and TV series Taboo. Talking of shameless, Michael Fassbender’s prominent nudity in Steve McQueen’s Shame made total sense – why would you feel the need to cover up around your bachelor pad if you live in narcissistic solitude?

Comic actors aren’t above dropping their trousers either if it means getting a laugh, be it Jason Biggs caught in another compromising situation with a fruit pie in American Reunion or Graham Chapman inadvertently exposing himself to his adoring disciples in The Life of Brian. Sometimes these dick jokes can even be artful: Jason Segel’s character being dumped while sans clothes in Forgetting Sarah Marshall is a perfect example. “It wasn’t gonna be a dumb joke where all of a sudden, for no reason, you see my penis,” said Segel. “It’s just such a raw moment that I think to add the nudity … it’s this mixture of shock and gasping and confusion.”

Another memorable moment of male nudity that delivers both shock and vulnerability is the brutal fight scene in David Cronenberg’s Eastern Promises, where Viggo Mortensen’s Russian gangster has his Turkish bath rudely interrupted by two knife-wielding (and fully clothed) assassins. The fact Mortensen’s most intimate areas are exposed and unguarded throughout only intensifies the fight’s nail-biting tension. For Mortensen, the nudity was purely practical. “I always knew the scene should be as realistic as the rest of the movie,” he said, “so I couldn’t feasibly keep the towel on.” If only more A-list actors had his balls.