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Clothing brands have been smuggling spandex onto the legs of unsuspecting men.

“I definitely didn’t explicitly understand what I was buying,” Austin Ray, a 36-year-old writer in Atlanta, told me. What he was buying were Gap Soft Wear Jeans in Straight Fit with GapFlex, which is a nine-word phrase to describe a two-word trend: stretch jeans. “Apparently I didn’t think too hard about what those words meant,” he said.

My friend David Covucci, a 34-year-old Brooklyn editor, also didn’t understand exactly what he was getting into when he picked a pair of Banana Republic Rapid Movement Denim jeans off a clearance rack, but the pants immediately felt different to him. “I knew something was up, but I didn’t Google until I got home,” he said.

If you wear women’s clothing, it might come as a surprise that a little bit of stretch is a relatively new concept for most men. Stretchy jeans have been common in women’s fashion for at least 20 years, but they’ve only found traction in the men’s mass market in the past five. Now nearly every major menswear brand offers at least one stretch option, and many go beyond the product’s tight-fit reputation with looser cuts.

To sell these jeans to men, though, brands face a conundrum common in the fashion and personal-care industries: How do you convince guys to buy something they believe is for women? In the case of stretch denim, brands have found success by obfuscating what their product actually is, allowing them to recast stretch pants as a tool of masculinity. Whether it’s GapFlex, Rapid Movement Denim, Wrangler’s Advanced Comfort, or just not mentioning the new fabrication at all, the theory seems to be that what men don’t know about their jeans can’t hurt them. Intentionally or not, these branding decisions have helped change the modern idea of what it means to look like a man.

Denim is traditionally 100 percent cotton, but mixing in 1 or 2 percent elastane (the generic name for Lycra or spandex) fibers gives jeans a softer feel and helps ease the adversarial relationship between the durable, rugged textile and tender bits of the human body. This particular fabrication is the relatively new result of advances in textile production, and it found its first home on the consumer market in the mid-2000s, when women’s fashion shifted its focus to skinny jeans and away from a more relaxed, boot-cut look. Women embraced the change quickly. You could be trendy and also be sitting down. It was a revelation.

Men, who saw fashion bend toward slim fits for them soon after it did for women, have been considerably more resistant to the change, which is what has prompted the euphemistic trickery from brands. For something as innocuous as slightly less restrictive pants, stretch jeans have caused a lot of hand-wringing among men’s-fashion types over the past couple of years. Much of it is bound up in what constitutes an appropriate performance of manhood, and whether suffering for fashion, something long considered a feminine burden, is something masculinity requires.

In opposition to stretch jeans stood the popularity of selvedge denim, an old-fashioned manufacturing method whose stiff, rough product found an ardent following among menswear enthusiasts online that hit a fever pitch a few years ago—long after women had largely embraced the ability to painlessly sit down. According to Matt Sebra, the style director of GQ magazine, the popularity of selvedge required men to buy into an overtly masochistic idea of what it means to be authentic and masculine. “You get this stiff-ass pair of jeans and people would tell you, ‘Oh, wear them every day for six months and don’t wash them,’” Sebra says. “The first two weeks, you’d need the jaws of life to get out of them, and you were just sweaty and scratched up.”

Nancy Deihl, a professor of fashion history at New York University, echoed Sebra’s feeling that the slow embrace of elastane among men was at least in part the result of how it violated the belief that masculinity requires testing and achievement. “Stretch jeans go against ideas of male authenticity—the Marlboro Man image that jeans are supposed to have,” she says.

So, the thinking went, what if the jeans were no longer stretch—what if they were centered around the practical advantages of having a full range of motion?

There are two main ways that clothing companies have chosen to rebrand sitting comfortably as an activity for men. The first is recoding stretch denim as an aid in athletic performance, even though modern fashion jeans aren’t intended to be worn for anything resembling exercise. It’s difficult to parse what kind of rapid motion Banana Republic expects its customers to undertake in Rapid Movement denim, for example, but evoking ideas of athleticism is a common tactic for brands trying to make a case to men for a historically feminine product, according to Ben Barry, the chair of the Ryerson School of Fashion. Invoking athleticism also helps conjure the comfort and ease of athleisure, which is used in other parts of men’s fashion—dress shoes with flexible, cushioned soles, for example—to promise buyers a more casual experience in disguise.

Nathaniel Freeman, Banana Republic’s head of men’s denim, told me the name sprang out of fit testing for the line, during which “a team member put the garment on and started doing lunges down the hall, telling everyone how comfortable and flexible they were.” (Other stretch-jean makers wouldn’t comment on their gendered brand strategies.) It was smart of Banana Republic to go with that impulse, according to Barry. “Associating stretch denim with sports lets men know it allows high performance, that it’s a fabric that’s staked in athletic wear, that it’s purely about durability and breathability,” he says. That gives wearers some distance from the show-off nature of women’s skinny jeans. “Of course it’s not about showing off or revealing the body, which would be associated with femininity,” Barry says.

Sebra agrees that drawing an association between sleeker silhouettes and sports helps men get over the trepidation they might have about displaying their bodies. “The idea of men’s bodies being shown off or illustrated through their clothes is a concept that’s relatively new to a lot of men because there are still so many hang-ups about the male form,” he says. In that sense, athletically euphemized stretch jeans might even be a bit of a gateway drug—the thing that helps men interested in fashion get over the hump and get comfortable with clothes that actually fit.

As Barry points out, though, there’s nothing inherent in slim jeans that’s masculine or feminine. “Fashion upholds gender binaries by associating silhouettes, fabrics, and colors with masculinity or femininity. The ways in which fashion has gendered styles as masculine and feminine shift across history and geography, or even among simultaneous subcultures,” he says. Take, for example, revolution-era France or the United States during the 1970s: Men in tights and ultra-tight pants, respectively, were the aesthetic norm.

So in trying to reimagine stretch denim as athletic, brands take part in a long tradition of shifting what we expect masculinity and femininity to look like. Those boundaries are always in flux, even if the concepts feel fairly static to the casual observer. Think about how quickly the personal-grooming standards denoted by the term metrosexual became commonplace among straight men, and how antiquated that term already feels just 15 years later. Sometimes people are ready for a change and they just need to find a way to talk about it.

The other idea that marketers have invoked to bring men over to the dark side of stretch pants is comfort, which appeals to a slightly less active, slightly less aesthetically concerned conception of modern masculinity. For men who wish they could wear their sweatpants to the office, both traditional brands and upstarts like the Kickstarter darling Alday are here to give them the opportunity. In doing that, they indulge the masculine belief that men should think about how they look as little as possible. There’s clearly a market for such a product: Alday’s Kickstarter sought to raise $15,000, but it ended up with more than $67,000 in support from backers who want to try a denim product that’s knitted like pajamas.

For plenty of men, that’s an intriguing proposition. Once they experience the difference between stretch and conventional denim, there’s no going back. Ray was delighted to find out that his jeans were more forgiving, even if he hadn’t expected it when he bought them online. “I remember I walked into the living room and was basically yelling at my wife about how much I loved them,” he says. “She confirmed to me they looked like regular jeans, and I was good with that.”

Covucci, on the other hand, had a moment of trepidation. “I wondered, ‘Did I buy jeggings? Am I a stretch-jeans guy?’” he says. It turns out he is. “They’re more comfortable, and it’s 2018. I’m a man on the go.”

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