Some are wearing them in jest. Others sport them sincerely.

Whatever their motivation, teenagers across the country have been going wild for shirts that bear a chaste declaration: “Virginity Rocks.”

The trend has puzzled some school administrators, who have banned the shirts only to face criticism, and other adults, who have wondered if youth abstinence is on the rise.

It can all be traced to Danny Duncan, a 27-year-old YouTube personality and prankster, who said he started wearing “Virginity Rocks” shirts in his videos as something of a joke in 2017. Duncan said that his use of the phrase was “tongue in cheek,” but he is proud to have seen it catch on with young people who champion abstinence.

Duncan has built a following of roughly 3.5 million subscribers on YouTube with his prank videos. And that audience has wholeheartedly embraced “Virginity Rocks.”

Duncan’s Shopify data shows millions of dollars in online sales. And a partnership started last year with Zumiez, the teen retailer with more than 700 locations in the U.S. and abroad, has increased his visibility.

The chain prominently showcases “Virginity Rocks” apparel online and in stores, where cardboard cutouts of the floppy-haired YouTuber grin at customers. The wares, which include bucket hats ($40), lanyards ($12) and slide sandals ($40), alongside the ubiquitous hoodies ($55), have been a hit. Duncan said Zumiez had told him that it has sold more than 400,000 pieces of merchandise.

The success has startled some in Duncan’s orbit.

“We’re doing these meet and greets for Zumiez and thousands of kids show up and the whole mall is covered in ‘Virginity Rocks,’” Stefan Toler, Duncan’s manager, said. “It started as more of a joke, but now it’s an actual brand where we’re outselling Thrasher, Nike, Adidas and all these brands in Zumiez, and we’re like, ‘What the hell?’ Even Zumiez is like, ‘What’s happening?’”

He theorized that those buying the “Virginity Rocks” apparel were split between teenagers who endorsed the message and Duncan’s fans, who were wearing it ironically. Still, he said, he believes that the popularity of the shirt is making virginity cool among Duncan’s supporters.

“I’m 32, so back when I was in high school you would not say that, but he’s made it cool with his fans in general,” Toler said. “If Danny’s fans are virgins, they’re psyched to be virgins.”

Duncan has a trademark for use of the phrase on clothing, greetings cards and condoms, according to public records. Toler said policing the trademark was “insane.” Still, he has been able to remove imitators on Amazon by using the site’s brand registry and has been successful when he has sent emails to sites like Teespring, which allows people to customize apparel, asking them remove items, he said.

For some school administrators, the clothing has presented a confounding problem. Teenagers have been suspended for wearing the shirts in Oregon, Wisconsin and Missouri. That has outraged parents, who believe the clothes are bearing a positive message.

One student at Roseburg High School, in Roseburg, Ore., was sent home in 2018 after wearing a “Virginity Rocks” shirt. The school told a local news outlet at the time that the shirt would have been disruptive in class, and that the same treatment would have extended to shirts that said “Sex Rocks” or “Smoke More Pot.”

“I don’t understand why you would ban it,” Duncan said. Plus, he added, “a lot of kids kind of like it when they’re not supposed to have it.”