At least on paper, Marvin Hyer Jr., 26, has one of the worst jobs on the planet. A full-time employee of Johnny On The Spot, a portable restroom rental service based in Old Bridge, N.J., he spends entire afternoons standing next to the one place at any outdoor event that most people avoid with extreme prejudice or visit only when absolutely necessary: the dreaded porta potties.

Hyer, 26, has a few more responsibilities than just opening the door for guests. “I have to make sure everything is stocked and organized and neat,” he says. “I also direct clients on how to use the porta potties and assure them that these are in fact restrooms.” It may sound redundant (Who doesn’t know how to use a porta potty?), but these “portable sanitation units” (the official industry term) don’t have much in common with the uninviting bathroom facilities found at rock concerts, public parks, and sports venues.

Johnny On The Spot, a 40-year-old company that services several Northeastern states, provides everything from Celebrity Restrooms (with an average rent of $300 per day), featuring flushing toilets, welcome mats, artificial flowers, magazine racks, and perfumed fragrance, to luxury trailers such as Diamond and Sapphire Series (averaging $3,000 per unit per day), which come equipped with porcelain sinks and polished brass faucets, not to mention stereo surround sound and air conditioning. “It’s fun to watch people’s faces when they walk out,” Hyer says. “They come in expecting the worst, and they come out saying it’s nicer than their bathrooms at home.”

But even with the high-end amenities, porta potty abuse is not uncommon—which is part of the reason attendants are necessary, just to discourage unsanitary hijinks. It’s especially rampant with teenagers, who, Hyer says, consider porta potties an easy form of entertainment. “I guess they did some prank with a porta potty in that stunt show Jackass,” he says, “so kids try to duplicate it. They’ll get in there and try to topple the unit over. And things get … messy.” Occasionally units will even be set on fire. “Once they get lit,” Hyer says, “it’s not easy to put out. And they burn fast.”

Hyer didn’t always want to be in the portable bathroom industry. His father, Marv Hyer Sr., is the longtime operations manager at Johnny On The Spot, so Hyer Jr. spent much of his youth around porta potties. He studied marketing and management at Western New England University in Springfield, Mass., and after graduating he interviewed with several non-toilet companies. But he ultimately decided to stay with the family business. “It’s near and dear to my heart,” he says. “I like it. It’s familiar to me, and I like taking it to new levels.”

Hyer Jr. has been involved with almost every position available at Johnny On The Spot. At 16, his first job with the company was cleaning porta potties after they’d been returned from customers—which he says was exactly as gross as it sounds—and during college he worked for a summer as a porta potty mechanic’s assistant. Now Johnny On The Spot’s marketing and sales manager, Hyer takes a shift as an attendant whenever one becomes available. (Most Johnny On The Spot employees work as attendants on a rotating basis.) He loves it for both the hours (“Attendants usually work on the weekends,” he says) and the pay (which starts at $40 an hour plus travel expenses).

Also, attendants are typically only hired for high-profile events, such as Jessica Alba’s wedding—Johnny On The Spot supplied the toilets, but Hyer wasn’t the attendant—and the Robin Hood Foundation’s benefit concert in New York City last month, at which Hyer got the plum gig as official attendant. Performers included Rihanna and Neil Young, and Hyer claims he never witnessed either artist using the portable bathrooms (or at least he’s unwilling to discuss as much on the record). He does remember, however, that Late Night host Jimmy Fallon and Saturday Night Live’s Seth Meyers, who performed for the event, both “referenced the luxury restroom trailers as part of a joke.”

It’s not just professional comedians making jokes at the expense of porta potties. Hyer has heard them all, and it’s virtually impossible to shock him anymore. “People will say things like ‘You must have a shitty job,’ or ‘You must take a lot of crap.’ It’s something you learn to roll with,” he says. “When you’re in this line of work, you can only take yourself so seriously.” But despite the temptations to play along with the jokes—which their porta potty competitors are happy to do, some of whom advertise with catchy and vaguely scatological slogans such as “We’re No. 1 in the No. 2 business”—Johnny On The Spot tries to maintain a professional image. And that means no potty-based humor. “We don’t hate the jokes,” Hyer says. “But we’re not going to be the ones to make them.”

So if you should find yourself using a Johnny On The Spot porta potty, and an attendant is waiting outside, probably overhearing more than you’d want him to, there’s no danger that he’ll bang on the door and shout “Hey, light a match in there!” Hyer laughs at the idea, but he’s quick to deny it. “That would never, ever happen,” he says. “I can guarantee it.”

(This story originally appeared, in a slightly different form, on the Bloomberg Businessweek website.)