When Brandon* was in his early 20s and studying abroad, he went on a trip to Israel with his friends to hike in the Judean caves. At a certain point, they reached a part of the cave that was pitch-black. “It didn't take long for someone to suggest we all jerk off in the darkness,” Brandon, now 35, says. “And so we did.” After they finished, they zipped themselves up and proceeded to continue meandering through the caves, as if nothing happened. They never spoke of it again.

Brandon self-identifies as straight. He had never masturbated in front of another man, let alone a group of other men, before in his life. Yet he says in retrospect, the weirdest thing about the incident was how not-weird it seemed at the time. “It was tame, fratty, kind of lame,” he said.

In truth, Brandon is absolutely right: his experience masturbating in front of other men is far from a singular one. Though there isn’t much data attesting to its exact prevalence, it’s far from uncommon for straight men to have had communal masturbatory experiences during adolescence, whether it’s beneath the alpaca blankets in their parents’ basement or behind the bleachers after gym class or in the bunks at sleepaway camp (or at John Lennon’s house). There’s even a term for it on Tumblr: “buddy bating.”

“We know it’s common for teenage boys to masturbate together or to instruct one another in how to do it,” says Dr. Jane Ward, author of the 2015 Not Gay: Sex Between Straight White Men, which coined the viral term “bro jobs” to describe straight men having sex with each other. Ward cites a 1981 report on male sexuality by sexologist Shere Hite, which suggested that nearly 20 percent of men had engaged in group masturbation during adolescence.

Most men who are willing to speak openly about experiences like this will do so with a certain measure of fondness, even nostalgia. “It's a rite of passage and an essential part of the teenage male bonding ritual,” says Sean*, 31, who used to buddy bate with his friends when he was in his early teens. Sean came of age in the early aughts during the pre-Pornhub, post-Limewire era, when online porn was far less accessible than it is now, so he viewed communal masturbation more as a matter of convenience and less as a display of budding masculinity. But regardless of the impetus behind buddy bating, for some men, the urge to whip it out in front of your bros extends beyond adolescence, even though there are fewer options for them to dabble in that interest in adulthood.

In Seattle, for instance, there’s the Rain City Jacks, a jackoff club for men who wish to, per the website, “jack off openly and safely in a uniquely sex-positive, non-discriminating and mutually respectful community.” (They also have Mardi Gras-themed events, if you’re into that.) Every Sunday and Tuesday, the Rain City Jacks meet at an erotic art gallery in Seattle. The furniture is covered in canvas, and volunteers hand out small plastic cups of lube to guests. (“We try to be environmentally responsible, but people want their own clean lube,” Rain City Jacks founder and organizer Paul Rosenberg told me.) The lights are dimmed slightly and soft music plays while the men gather, either alone or in small clusters, and proceed to jerk off, all the while keeping conversation to a minimum to ensure everyone stays in the moment.

One of the terms I hear a lot is that this is the ultimate form of male bonding.

Most of the attendees at Rain City Jacks are gay men. But Rosenberg says it is not uncommon to see curious straight men at the club’s events. He conducts annual surveys of the group, and he says that while the majority of members are gay, about 10 percent of the Seattle Jacks’ 300 or so members self-identify as heterosexual, with 25 percent identifying as bisexual.