a La Perla bra, he says, or a gay man in a jock strap. But the quotidian, mundane nature of grey sweats — who amongst us doesn’t own a pair? — adds to their accidental eroticism.

“Many people are hot for nudity that’s somehow obscured,” says Tina Horn, host and producer of the long-running fetish podcast Why Are People Into That?! and the writer/creator of the sci-fi sex rebel comic SfSx. “It’s all about exhibitionism and voyeurism. The sweatpants exhibitionist gets the plausible deniability that they’re not showing off, and the sweatpants voyeur gets the thrill of witnessing something, like a dick, that they’re ‘not supposed to be seeing.’”

Horn notes that people usually fetishize tight clothing — latex, spandex, rubber — which, viewed through a Freudian lens, “could represent a return to the womb, or a full body embrace.” So, conversely, a preference for soft, loose apparel could be interpreted as some kind of release or freedom from compression. “It's all about perverting the mundane, which is just a fundamental function of human sexuality,” she said.

“When I see someone in sweatpants, it’s like they either have no need to be presentable whatsoever, or they’re so cool and confident they’re just wearing what makes them comfortable,” says Alex Gorosh, a California-based director and editor. While he hadn’t heard of Grey Sweatpants Season™ he says he always thought that “a person in sweatpants was sexy.”

“It’s like they’re so confident, they’re so comfortable, and that’s sexy,” he continued. “So you want to be with them.”

Designer Scott Sternberg, whose brand Entireworld’s calling card is its downy sweatshirts and pants, surprisingly, hadn’t yet heard of this phenomena. “I’m not a meme person, but I totally get it and it makes complete sense,” he said by phone, chuckling. “Sweats get this bad wrap for being shlumpy clothes you wear when you’ve given up. But I think there’s something really sexy about a guy in sweats. There’s this very I-just-got-out-of-bed-and-threw-it-on sort of thing, you know? Like, maybe he’s not wearing underwear.”

When he was first developing Entireworld, Sternberg said that ideas about “sex” and “skin” were foundational parts to the brand’s identity, but not in a “porn-y or vulgar” way, he said. Instead, his work hints at something sensual, but in an off-handed way. “Loungewear is very intimate,” he said. “It's like something that may have a Cheeto stain on it, but once you wear that out of the house, there’s something that becomes inherently sexy about it.”

For his part, Sternberg was obsessive about the fabrics, and developed his sweats up from the yarn to have just the right feel and look. That yielded a textile that was soft and fell just so. “It’s drape-y, it's sexy … it hugs the peen.”

It seems as if Sternberg was onto something. According to the global fashion search platform Lyst, grey sweatpants, as a category, grew 14% year-over-year from 2018 to 2019, and 38% this year over last. Data-wise, grey sweats historically hit their search peak from September to December, though this year, due to the COVID-led rise of cozycore, there was an additional spike in mid-March and April. Nike was the leading brand, with a 40% spike in search over recent weeks.

Twitter says that since 2015 there have been more than 1.5 million tweets about Grey Sweatpant Season, with 4,300 in September of this year alone. According to its data, the conversation peaked in 2016—though, anecdotally, that conversation may have just migrated to platforms like Instagram and TikTok in recent years.