They don’t call it “the oldest profession” for nothing.

My Granny the Escort, a new documentary that aired this week on Channel 4 in the UK, aims to demystify “mature escorts”—women over the age of 60 who choose to have sex for money. Directed and narrated by Charlie Russell, the film opens with a chirpy, Kiessling-esque tune, followed by a vague title card that reads “Somewhere in England.” We’re then transported inside a cozy suburban home. A curvy woman, dressed entirely in black, gingerly ambles down the stairs, nearly tripping over the bottom step. This is Beverley, 64. She is a grandmother and a prostitute who operates out of her humble abode. Charlie’s scheduled interview, however, is suddenly interrupted by the arrival of a client 20 years her junior.

“I’d come to find out about Beverley’s life as a ‘mature escort,’” says Charlie, “but I found myself waiting awkwardly in her kitchen as she had sex with a stranger above my head.” The creaking of the bed can be heard through the floorboards and, 20 minutes later, Beverley emerges, giggling.

“How was it,” asks Charlie, 33. “It was very nice, actually!” replies Beverley.

Prostitution is legal in England provided the person selling is 18 or older, and it’s not done in public. And of the estimated 100,000 prostitutes in the United Kingdom, a small—but formidable—percentage of them are classified as “mature.” Over 45 minutes, Charlie’s documentary follows three of these women and examines why a woman in her later years would choose to be a prostitute, as well as what would compel a man his age to pay for the sexual services of a more mature woman.

Beverley’s been an escort for 25 years, currently charging 50£ for a half-hour and 90£ for the full hour. She began because, she says, “my ex-husband left me penniless. He was a gambler, unfortunately, so we literally had nothing. We were living on bread and jam.” When her husband left she was forced to raise the kids on her own and one day, she saw an advert in the paper that said “Escorts Wanted.” She rang them up, expecting to be compensated for, perhaps, accompanying a gentleman to lunch. When the man arrived, he told her they were going to do “the rounds,” and by the end of the day, she’d had sex with eight different men.

“When I got home, my son ran me a bath and that’s when I got upset because I thought, ‘Oh, my God, what have I done?’” says Beverley. “But then I looked at the money and thought, ‘Well, at least we’re going to eat tonight.’ Once I got over the first day I was fine. I just worked, and worked, and worked. It was just a job at the end of the day.”

When Charlie asks if it’s dangerous for Beverley to have strangers coming in and out of her home with no security present, she says, “It is… but without their clothes on, they’re usually the vulnerable ones.”

Sophie, a masked woman in her 60s, is the next subject. She’s been working as a prostitute since her late 50s, and lives in the countryside, where it’s easier for her to service her clientele—which include 20-year-old boys, 30-year-old Swedish businessmen, and 80-year-olds—without causing too much fuss. According to the film, she services 100 men a month and works six days a week.

“I’ve never turned anybody away,” she says. “There’s always something to like about people.”

Before her days as a prostitute, the Liverpudlian used to work six-and-a-half days a week at an office and “never really had time” for her own private life. Her husband left her after two years, and she was forced to bring up the children on her own. She says she “didn’t really date” during this period “because I didn’t really feel it was right for [the kids] to have many people in their lives coming or going.” On her youngest son’s 18th birthday, she realized that she wanted her life back.

“I said to him, ‘Happy Birthday! My parental responsibility has endeth,’” she says. These days, she’s lost contact with her children, and keeps all of the relics of her “old life” in a suitcase. “That life doesn’t really happen anymore,” she says, zipping up its contents. “I just moved on and created another one.”

Then, we meet the film’s most curious subject: Sheila Vogel-Coupe. At 85 years young, Sheila has been labeled the oldest prostitute in the UK, and as such, charges upwards of 250£ an hour. She looks like your typical granny—gray hair, wrinkles, dentures—and slowly stumbles about her apartment in a magenta tracksuit. “This is my office,” she says, smiling and pointing to the bed.

“Men, especially young men… they see something about me which is a nice feeling,” says Sheila. “Often, men call me up and they say, ‘Will you please go on talking because you’re turning me on and I have such a wank when I’m talking to you.’” She laughs. “I know I’m very, very sexy.”

Sheila’s been escorting for the past four years, ever since her second husband passed away. But she hasn’t left her flat in the eight weeks since she underwent an operation to have 33 cm of intestines removed. She stumbles over to the bathroom and points to the bathtub. “Sometimes, they come in here, I plop them in the bath, and that’s what they call ‘waters ports’—when I stand on top of them and let them have the golden flow.” She’s determined to recover from her injury and get back to full health so she can continue to service clients in luxurious London hotels. Prior to her operation, she saw approximately 10 clients a week, and despite being out of commission, has several men chasing her via text, begging for her company. “It’ll only take 5, please!” reads one desperate text.

Three years ago, Sheila’s life was turned upside down. She was headed to a local hotel for a job, when all of a sudden the tabloid News of the World caught her, and ran her picture on the cover with the headline, “GUM AND GET IT.” The rag targeted her because her granddaughter, Katie Waissel, was a contestant on the reality singing competition series The X Factor. Sheila has three daughters, three grandchildren, and two great-grandchildren, and none of them knew about her career change until the tabloid leak.

“What happened as a result of it was you’d think I had committed a murder,” says Sheila. “They couldn’t believe I’d do something like that. I told them, ‘What do you think I’ve done?’” She pauses. “Everyone thinks about things differently. I tried very hard to patch it up, but then it got to the point where they wanted me to promise that I’d never ever do it again. I said, ‘Tell them to stuff it up their…’”

We also meet two disguised “punters”—or “johns”—who explain why they repeatedly enlist the services of mature escorts. “They’re confident. They know their own bodies,” one of them says. “It’s almost, for me, a bit perverse, like ‘Women of that age shouldn’t be doing this.’ That’s different, isn’t it? They’re batting outside what is kind of expected of a grown-up lady and that… that’s naughty.” He adds, “If I compared the experience of a mature lady to that of a younger girl, it’s a contractual interaction, but there feels more value to it and more depth to it. And it isn’t just wham bam thank you ma’am. A mature lady will provide you with the feelings that you’re important—you’re the one—whilst at the same time clearly enjoying it themselves.”

Another carries around a “punter’s bag” with him consisting of cocoa butter, lube, tissues, an ice pack, and a towel. “There are a lot of people who are just awkward and not very outgoing,” he says, “and I think I fall within that broad range of people, and I think it’s great that you can go and see a mature working girl and she will make you, for that one hour, feel great.”

My Granny the Escort concludes with two of the women reaching a crossroads of sorts. Beverley, in her 25 years of escorting, has never had a boyfriend, so she joins a dating site and is determined “to wake up with someone you can cuddle.” As for Sheila, well, she knows her days as an escort are probably numbered, but isn’t ready to hang up her heels just yet. She admits to her eldest daughter, Josie—the only relative that still speaks to her—that she can’t stand being alone. “It’s lovely to still be sexy at my age,” she says, “but I’ve been on my own now for the last eight, nine years, and I do get lonely. I like the companionship of a man, of a gentleman. Whatever may come with it, okay fine, but it is the companionship of being with somebody.”

As for the disguised Sophie, well, she’s resolved to take Sundays off and give herself one day a week to “keep a foot in the real world,” but has no plans of quitting any time soon.

“I will have a boyfriend for an hour, I will have a lover for an hour,” says Sophie. “That’s enough. No dirty socks to wash.” She takes a long pause. “You know, what I do, some people would classify it as ‘immoral,’ but you know? I really love it. And why shouldn’t I be able to do what I want to do? And if people can’t accept it, well, it’s just one of those things.”