Owen Dennis Riley, 17, has never had a girlfriend. But he plays a boyfriend to at least half a million subscribers on YouTube.

He brings you gifts on Valentine’s Day and soup when you’re sick. He serenades you, if you’re into that sort of thing. Most important, he wants to help you get a good night’s sleep. Instead of counting sheep or limiting your screen time before bed, he’ll talk you down for the night and tuck you in.

“Babe, baaaabe, what I want you to do is just take a deep breath in and a deep breath out,” he says in a whisper at the beginning of a video titled “Loving Boyfriend Does Your Makeup.” “Everything is going to be O.K. It’s all right that we’re going to be a little bit late to the restaurant. I called them. They said it was O.K. if we’re a little bit late as long as we get there within the hour. So just calm down, I’m going to be here, I’m going to give you some support. I don’t want you to stress, all right? I tried to get here as quickly as I could because I know you start to get really stressed in these types of situations. But don’t worry because I’m here now, so you don’t need to worry anymore.”

He proceeds to tickle the camera lens and microphone with makeup brushes, promising that you really look better without makeup, anyway.

His YouTube channel, DennisASMR, is one in a growing genre known as “A.S.M.R. boyfriend role-play.” This combines the popular techniques that may cause people to experience “brain tingles” — the hallmark of autonomous sensory meridian response — with the doting behaviors often attributed to good romantic partners.

Owen isn’t the inventor of this format. According to Craig Richard, an A.S.M.R. expert and a professor of physiology at Shenandoah University in Virginia, boyfriend and girlfriend role-play videos have appeared on YouTube for at least five years. But Owen has certainly helped popularize them. In May, Emma Chamberlain, the teenage mega-influencer, parodied him, the ultimate marker of YouTube fame.

Like many other entrepreneurial teenagers, the Supreme resellers and meme makers, Owen was just looking for a way to expand an audience. After various fruitless endeavors — singing, doing pranks with his siblings — he turned to A.S.M.R.

“I thought it would be easy, and fun — it was summer break and I was bored,” said Owen, who is home-schooled. “Helping people” appealed to him, too. His early A.S.M.R. videos, featuring finger flutters, mic-nibbling and breathy storytelling, began racking up millions of views. One commenter suggested that he try boyfriend role-play.

“I thought I could do it in my own way,” Owen said. “I come from a Christian background. I don’t want to do anything that will affect my integrity, which is wholesome.”

“I had a moment where I realized that I think I can make it cool,” he continued. “I thought I could do it in my own way, something more realistic and natural — for teenagers. I wanted to create something that my viewers won’t be afraid to be caught watching.” (Most of them are women between the ages of 18 and 24, according to demographic data Owen provided from his YouTube dashboard.)

Models of Care

Owen lives outside of Savannah, Ga., with his parents. Often, when he is recording, they’re in the other room, aware of the content he is making and sometimes involved in the creative process.

“My family is so supportive,” he said. “They thought it was cool I could get that many subscribers from whispering into a microphone.” And those subscribers mean views, which means money. But just how much?

“For every 1,000 views, I make $3,” he said without a hint of braggadocio. The views on his role-play videos range from 155,000 to two million. “You can do the math.”

The comments on a DennisASMR video often encompass a range of emotions, from enamored to creeped out. (Viewers also pose questions about his personal life.) These extremes revolve around the intensity of Owen’s eye contact and the weight of his validating statements. How did this teenager develop such deep emotional intelligence?

“I based it off my mom and how she would treat me,” he said. “She would give me soda, crackers, you know, but then I changed into a boyfriend to make it sweeter.”

Watching his parents’ happy marriage of 20 years has also inspired him. The videos, in turn, present examples of the validation and affection he wants for himself.

“I have dealt with the same things my viewers have: anxiety, insomnia and depression. And I’ve never been in a serious relationship, so I know how loneliness feels,” he said. “I know how it all feels, so I can help give them what they’re lacking.” Judging by his latest videos, that includes a real-life superhero, “smexy” mouth sounds and, of course, someone to talk to before bed.

Is It Scientific? Troubling? Both?

According to a paper about a functional magnetic resonance imaging (fMRI) study by Dr. Richard and others, the brain regions that are activated by the personal attention implied in an A.S.M.R. video compare to those that are activated with real-life caregiving, particularly in emotional arousal and reward. “Someone pretending to care registers as someone actually caring for us,” he said.

Dr. Richard’s study observed only a small sample — 10 people — and research on A.S.M.R. is nascent. Some psychologists aren’t convinced that the videos benefit anyone.

“This kind of role-play is used to create an understanding of what is normative, and teenagers seek it out in an authentic way,” said Caroline Fleck, a clinical psychologist and an adjunct instructor at the Stanford University School of Medicine. “This is acting as template for viewers, and that’s an issue.”

She referred specifically to Owen’s “Jealous Boyfriend Roleplay (Sleep Inducing)” video, which has accrued nearly two million views.

Dr. Richard agreed that this particular video doesn’t fit the A.S.M.R. standard. It features a ruder character, whom Owen admits he channeled to make the videos feel more realistic, so his oeuvre wouldn’t consist solely of “perfect moments.”

To Dr. Fleck, however, “Jealous Boyfriend” not only defies the social norms of A.S.M.R., it’s also problematic. The comments on the video echo her sentiment.

‘Wow… he actually made me upset and feeling guilty at the same time. And I should not even be feeling these things. I haven’t done anything,” one user wrote.

Another wrote: “I couldn’t fall asleep because I was too invested in the drama.”

Even the more benevolent videos raise red flags. “It is absolutely not realistic behavior,” Dr. Fleck said. “Being alone with a guy in your room when you’re having trouble sleeping is not going to look like that.”

Alexandra R. Lash, a clinical psychologist in Portland, Me., has concerns that watching too much of this kind of role-play may cause an “unrealistic and idealized perspective of what a partner can or should be.”

Echoing her concern, Dr. Fleck said that “the subliminal message in these videos is that the viewer needs someone to take care of them in order to fall asleep, and that’s a notion we try to fight against in mental health. Believing so interferes with your ability to take care of yourself.”

Our Screens, Ourselves

Anyone who has seen a sleep psychologist has heard it: Screens and sleep don’t mix.

“Studies show that the blue light emitted from screens decreases melatonin production in the brain,” said Whitney Roban, a sleep specialist in New York. “So if you’re watching a video in bed, your brain and body are being told to stay awake.” The interactive nature of these videos, she said, also defies the basic tenets of sleep hygiene.

“My first line of defense against insomnia,” she said, “would not be to get a boyfriend.”

Or a virtual boyfriend. Dr. Fleck warned that the videos shouldn’t be a substitute for real-world interactions. “What if YouTube is causing us to withdraw, and now we’re using YouTube videos to get our needs met?” she said. “Looking into someone’s eyes can cause the release of oxytocin, even if there is a screen between you.”

At the end of “Boyfriend Tucks You in at Night,” Owen looks directly into the lens, with eye contact so intense it may feel natural to look away. He drums his fingers on the spine of a book and asks, “Did this help? Are you feeling more relaxed? I’ll text with you if you still can’t sleep, but I think you’ll be fine.” He smiles reassuringly, before squeezing in an ad for a weighted blanket.