They don't scream affirmatives, call out to God or whip their hair around like a tornado. Then we'd know they were faking it.
But men fake orgasms too, for myriad reasons - not least of which is sparing their partner's ego.
A recent University of Kansas study of nearly 300 college-age men and women found that 28 per cent of the men had faked an orgasm during intercourse.
Why? Many knew a climax wasn't in the cards. They were seeking to end the sex without hurting a partner's feelings, the authors write in the study, published in the November issue of the Journal of Sex Research.
Beyond the why's are the how's: Wearing a condom helps to conceal the evidence (or lack thereof), as does an audible sigh - hardly the theatrics of Meg Ryan's Sally Albright in the infamous deli scene in When Harry Met Sally.
And while Sally digs into her coleslaw with a smirk after faking a colossal orgasm at the table, there is a clear double standard, with male faking viewed as more duplicitous than the female variety.
"Women can kind of see the humorous side of faking it. It will never be a point of pride for any guy," says James Bassil, editor-in-chief of lifestyle website AskMen.com. "They see their inability to climax as a reflection of their masculinity. It's caveman stuff, which is why we don't admit it to each other at work."
For its 2010 Great Male Survey, AskMen.com asked more than 100,000 men if they had faked an orgasm during intercourse. An average of 16 per cent said they had done it repeatedly; an additional 14 per cent admitted to faking, but just once.
"For the most part, it's not finishing on time or taking too long," Mr. Bassil says, noting that readers also said they will do it when they "finish too early and are embarrassed to show it."
"There is a pressure that both men and women feel to demonstrate pleasure to keep their partner happy."
Besides this pressure, guys fake it because they're tired, or uninspired. In comments made in response to a Salon.com post on the Kansas study, "DetroitRiverGuy" confesses, "I've faked it more than once. Sometimes it's just boring and the quickest way to end it is pretending to get off. Women don't have the monopoly on wanting to get some sleep."
Other men pretend to climax because they feel they have not managed to do the real thing "on time." It's part of a stringent sexual script that borrows mainly from porn, where actors often have their orgasms simultaneously. When two people endeavour to choreograph their O's, the end result can be that both feign it.
"On more than one occasion, I've counselled couples where each of them was faking it, but the other didn't know. It's a stunning realization," says Ian Kerner, a New York-based sex therapist who wrote the influential tome She Comes First: The Thinking Man's Guide To Pleasuring A Woman.
Although some couples see the big fake as a relatively simple way to spare themselves a painful conversation, they only lose out, Mr. Kerner says. "It's the little white sexual lie that has become a much larger, more ingrained form of deception. Couples ... lose a teachable moment in their sex lives where they could have really communicated."
Partner's feelings aside, the bluff has much more to do with delayed ejaculation, a growing problem for men, experts say. SSRI-based antidepressants are partly to blame because they can delay or even stamp out orgasms, Mr. Kerner says.
But a more universal culprit may be Internet porn: "More men of all ages are masturbating more," he points out, adding that it can lead to an "idiosyncratic masturbatory style" that desensitizes men toward their partners.
Porn has habituated many men to a terrain of "visual novelty" so vast they now have trouble focusing during real intimacy, Mr. Kerner says. "I think we're going to see more and more young men experiencing this," he says.
And if you're caught faking? "Many women become angry. Some are stunned that a guy would fake it," Mr. Kerner says.
Women aren't the only ones being hoodwinked. Evan, a 27-year-old Toronto man who did not want his full name used, got busted on his second try with his male partner.
"The second time I tried to fake it, he totally knew," Evan says, adding that he did it to "keep up" with his energetic boyfriend. "It was mostly having a younger partner and trying to please him by being satisfied. Sometimes it takes me a bit longer than it takes him," he says.
He's a bit more blunt today. "Now I don't fake it. ... I tell him how hot he is and how much fun it was watching him."
Why do men (and far more women) risk getting caught instead of having a bedroom chat? "Most of us are raised in a culture that eroticizes silence, and that correspondingly teaches us that talking about sex will ruin the mood," says Peggy Kleinplatz, a professor in the faculty of medicine at the University of Ottawa who also has a sex therapy practice in the city.
Dr. Kleinplatz says problems arise because people do not pay enough attention to how sexually aroused they feel when they begin to have sex. "To the extent that people are having sex based on external cues, without really checking in with themselves or each other to see how aroused the other feels, it may take a very long time to get to the point where they're close to orgasm."
She points out that men using drugs such as Viagra, Levitra and Cialis to increase the "staying power" of their erections (and women using lubricants) may mask the fact they are not all that excited. "Now what are they supposed to do? How are they supposed to make the sex end?"
In a study being published in January in the British journal Sex and Relationship Therapy, Dr. Kleinplatz notes that the past decade has seen an increase in clinical reports of delayed ejaculation in men. She is positing a link between erectogenic drugs and delayed ejaculation, as well as a link to lack of orgasm.
"Isn't it interesting that both of these things seem to have been reported right after the release of Viagra, Levitra and Cialis? I'm asking the question: Is there a connection?"
Ultimately, though, the issue may be one of optics. "The problem is that we're focusing on performance over pleasure," Dr. Kleinplatz says.