It isn't that men don't orgasm in movies - I'm sure I recall various grunts and moans from male actors in all the sex scenes I've seen, indicating pleasure of sorts - but in most cases the camera is trained on the woman's face, to show her expression of all-consuming delight. In The Big Easy, for instance, Ellen Barkin is reduced to mush with a few minutes of fingering from Dennis Quaid, while in Rust and Bone, the camera stays on Marion Cotillard for the sex scene, playing an amputee who gets fucked back to life in a few cursory missionary thrusts from Matthias Schoenaerts. The implication, I think, is that to be shown at orgasm is to display your vulnerability: therefore, these scenes represent an act of power over the women by the men, who are able to find the key to their moment of powerlessness. To flip the switch would mean casting men as submissive, since to orgasm is to lose control, make yourself defenseless.
Supporting this idea: an interview of Xavier Dolan in December 2016 by Vulture magazine, in which he is asked about his lack of inhibition, for a sex scene in I Killed My Mother, in which he bottoms. This shows that sex is still rigidly coded, perceived as an act of dominance, of doer and done-to, and that to be marked as the receiver of pleasure is to be stripped of your power. One onscreen male orgasm, that of Louis Garrel in Bernardo Bertolucci's The Dreamers, backs this up. Garrel plays a teenager caught up in a game of sexual daredevil with his sister (Eva Green) and an American visitor (Michael Pitt); his orgasm comes when his sister browbeats him into masturbating in front of them, and the scene shows that she is using power over him, making him retreat into a private sphere and display his secret self.
In certain gay films this imbalance, this actually rather ludicrous and harmful misapplication of antiquated sexual roles, can be redressed, although as we saw with the Dolan interview, ideas of dominance cross over into homosexual representations. Stranger By The Lake is a rare film to show male orgasm, although the film does it in a couple of ways - once with an actual cumshot, and on another occasion with a discreetly lit shot of two men cumming together, silhouetted against the night as it falls around them. In Brokeback Mountain, whose lone sex scene (one less than Annie Proulx managed in her short story) I only dimly remember, I believe the act is shown as a succession of gestures, fumblings and thrusts, rather than dwelling on a facial expression of pleasure or surrendering of a body to throes. Again, this is a nonsense: in the original short story, the cowboys' connection is primal and deeply sexual, with Jake telling Ennis at one point how much better it is with him. When Proulx's cowboys rush off together, abandoning Ennis's wife, it's because they are overcome by their desire, and Proulx sweetly talks of them "jouncing" a bed together. Scenes depicting this joint surrender to ardour and pleasure together would give a better idea of what connects the men than the ludicrous scenes of them arguing by a river like two old queens. But again: showing that racking physical transport, the visual depiction of vulnerability, the complicity and sweet innocence of cumming, would mark these men out as not manly, and I don't think an actor in Hollywood would take the role.
The Spanish film 10.000 km by Carlos Marques-Marcet provides a thrilling counter-example, starting with a long and terrifically well acted and choreographed scene that culminates in sexual intercourse between the protagonists. The camera remains with the man and woman as they talk and gradually give over to sex, building up progressively to pleasure felt by both but an orgasm that conspicuously judders through the man, as his girlfriend rides him. It's a clearly intentional and feminist decision, which shows us in a realistic and warm way a man who is deeply connected to his partner, and - as couples are - willing to surrender to a moment in her company. Their smiles and laughter in the moments afterwards, as the camera stays on them, show the well-crafted authenticity of the moment, and establish a connection that will be of great emotional importance to the rest of the film, as their bond begins to crumble.
Plenty of other scenes from other films underline what an outlier this film is in cinema. Certainly in films depicting heterosexual intercourse, the man retains a facade of power throughout sex in most instances, and the exceptions are rare. The extraordinary rarity of cunnilingus on film, compared to its (as I understand it) common practice among heterosexual companies, corroborates this sense that films are unwilling to show men in a submissive role. In 2016, A Bigger Splash's best sex scene involved Matthias Schoenaerts going down on Tilda Swinton, which goes hand in hand with his easy sexuality, his depiction as a modern, fluid man. Before that, I recall The Cooler (which I admit I haven't seen) meeting with extraordinary reactions in 2003 for, apparently, including a scene where William H. Macy eats out Maria Bello. This sense that going down on a woman would represent a loss of face to a man crosses over to most sex scenes in Hollywood, or even in Europe, where women are constantly depicted taking pleasure from vaginal intercourse unpreceded by foreplay. Needless to say, cinema is replete with blowjobs, from Pretty Woman to Casino via The Man Who Wasn't There.
Paul Verhoeven's Elle, out in the UK this year, gives the lie to these ideas, in a sex scene that is gutsy and liberating, as Michele, played by Isabelle Huppert, is overcome by a kind of auto-delayed orgasm that she takes pleasure in on her own, after the act, away from the man, and whose seismic seizures freak out her abusive lover, turning the tables on his twisted acts. In this instant, we see that female pleasure is its own beast, is not submitted to or bound by male power. It's a sharp and beautiful retort.
Meanwhile, we're still waiting for a commensurate depiction of male sexual ecstasy onscreen, in not just one but several, many films, films which could show men divesting themselves of inhibitions, self-awareness, and hideous, defeating power roles. Films which might show kind, sexy, good men generously giving and happily receiving sexual gratification; willingly abandoning themselves to a moment of true defenselessness; charmingly and with no afterthought displaying the full expression of that gladly seized vulnerability.