Jack is in his 30s. He is good-looking, makes money and has a nice apartment, and in this city, what all that gets you is almost everything. He meets me on Greenwich Street one morning for black coffee. Two girls he knows come walking by. He smiles, and his blue eyes are warm, but on one girl’s face, you can see that whole wringing week she waited for a call.

You’re Jack, and you take a girl out to dinner at Blue Ribbon, and she spends three hours deciding if you’re the kind of guy who will like her more if she sleeps with you or if she doesn’t. If you like her enough, it will mean East Hampton on Memorial Day and Nantucket on Labor Day and New Canaan for life. And God help her, there will be golden retrievers.

Jack can have any girl he wants. A blond event planner who wears heels on Sunday mornings. A former fit model who looks great in Hanes white. A yoga instructor who makes him spicy tempeh wraps with steamed kale on the side. There are girls who make great bloody Marys, and there are good girls who go to church on Sunday with their families, but last night, they were at Jack’s. There are girls who ride horses and lawyers and designers and tall ones and short ones, stacking their needs up across his walls and then saying those are not needs, they are shadows.

So why does Jack prefer escorts?

One night, Jack comes over to my apartment. He brings over a girl named Kimberly (her fake name) who says she’s 24 (her fake age). She’s wearing jeans, a black scoop-neck shirt and tall black suede boots. She looks like the part of Florida she’s from, sun-pressed and squeezed out into a glass.

She and Jack have this easy back-and-forth, sitting side by side at the kitchen table. They’ve known each other for about a year. He found her on Backpage.com, which is where people like Jack have gone since Craigslist shut down its adult services section.

The first time, she gave him oral sex. She came over to his big apartment, and it was a blinder date than usual because Jack was looking for a quick fix. Normally, he does his homework, using Eros.com, which is an escort directory, and The Erotic Review, or TER, which is Yelp for the sex trade, where johns trade information about the escorts and offer specific statistics. Hair length? Photo accurate? Shaved? More than one guy at a time? Full, no-rush session?

Created a decade ago by a john who was tired of being misled, TER sees about 350,000 visitors per day, men between the ages of 35 and 55 with a median income of $80,000. They wax nostalgic about Mistress Natalie and Emma of New York, and if you pay for a membership, you too can read about how WkndWhacker found VIP Daisy’s breasts even fuller in the flesh than they looked on her website and how the way she kissed was like “honey warming in his mouth.”

At first, it seems like a niche thing, and then one night, a bunch of guys have four Coors Lights, and one general counsel says to another, “Wait, so what’s your TER handle?”

The guys refer to themselves as hobbyists. The hobby is sleeping with beautiful women and then reviewing and categorizing them. It’s as routine as Zagat, clinical in its ratings, exuberant in its quotables and so much a part of a hobbyist’s daily throttle that a group of escorts recently offered a holiday discount to johns who make donations to the K.I.D.S. Hurricane Sandy relief fund.

Many of the girls provide the girlfriend experience, or GFE. They rub your back, and you take them to dinner, and they are in tune with politics, so you can say how you feel about Obamacare. You share some Kumamotos and Sancerre, and then you cab back to the Waldorf.

There’s Venezuelan Goddess, who has long black hair and D-cup breasts in a lace demi and ankle cowboy boots. There’s Bai Xi, who always pops up in the top 10; she’s small and Asian and replies to emails promptly. There is Jessica, with her Farrah Fawcett waves and Eastern Bloc lips. She says, “I have very long blonde hair & soft skin with amazing eyes & great smile. My outgoing personality will have you feeling very comfortable from the moment we meet, as if we have known each other for years.”

And that’s the main ticket. That’s why guys like Jack hire Jessicas for $1,000 per night instead of paying $200 for dinner with the lawyer who has a CrossFit addiction. The Bai Xis give you the same thing. Why go out with a wife in training when you can go out with the perpetual girlfriend? She puts out every time, like she’s bucking for a rating, while the wife in training wants to know why you didn’t walk the four flights of her walk-up to collect her for dinner. She wants your mornings. The girlfriend only needs your nights.

You arrange to meet a married john at a place where a married john would go to meet an escort. There’s a bar on the seventh floor of the W New York hotel called the Living Room. It has white leather and no windows. Constant bachelor nighttime. Mitchell arrives, all high-low in monogrammed French cuffs, a great suit and a Kenneth Cole Reaction tie. He carries a briefcase—he’s the general counsel of a CPA firm, which he has been with for more than 30 years.

Mitchell’s a master hobbyist. He sees about 25 girls per year. He makes more than a million annually and spends about $50,000 per year on the hobby. He pays a minimum of $500 per hour for a girl and doesn’t price shop. Mitchell has a girl in every city he travels to. I know his New York girl. Her work alias is Katelyn, and she’s a blond Australian with large breasts, a small waist and an equestrian face. She charges $5,000 for an entire evening.

They catch up on the couch for 45 minutes. There are tagines from her trips to Morocco and sweet-smelling candles. He tells her about the grandchild he’s raising with his wife. She tells him about her dives in Mexico. After a glass or two of wine, they start to kiss. Every man I speak to about Katelyn talks about the way she kisses. Deep French kissing. DFK.

“She is also incredibly smart,” said Mitchell. She was a marketing executive in another life, and she is well-read in the classics and on current events. She reads a lot about human psychology, and she understands the pathos behind the desires she fulfills.

“She will send me a catch-up email every once in a while, when she hasn’t heard from me.” Over Super Bowl weekend, she sent pictures of herself dressed in a cutoff jersey and boy shorts, exulting over a play on the television, on her knees on a white hotel duvet.

Mitchell calls his hobby “seeking relationships outside of marriage.” He has sex with his wife only sporadically. She’s overweight again. A few years back, she lost 150 pounds, but now she is back in the upper 200s. “I don’t see it as cheating,” he said. “I believe what she doesn’t know won’t hurt her.”

It’s 2 a.m., and Kimberly is drinking orange juice. She is talking to me and Jack about some of her other clients, the fat ones and the grandpa types.

“Are the old ones difficult, because they take so long?” Jack asked.

She laughs and punches his arm. “There are tricks,” she said. “But guys will do anything to just come. This one guy rolls in with a colostomy bag, and it broke my heart.” This was at the Waldorf.

“But this guy,” she said, jerking her thumb at Jack, “this guy is like the dream client. You walk into his door, and he’s good-looking and sweet, and he, like, makes you any drink you want, and he doesn’t even want to get laid most times. And in case you couldn’t tell, he can have any girl he wants.”

On nights when she’s not working or she hasn’t had a call yet, Kimberly will let Jack take her to a hookah place in the West Village. He’ll pay for her dinner and her smoke but nothing else, and she’ll check her phone and leave when she needs to.

“She’s like my buddy,” Jack said. “That’s what the girls I date don’t understand. We can have a nice romantic night together or whatever, and then I don’t text her for three weeks, and she doesn’t even miss me.”

“I always miss you,” she said to his face in the mirror.

“Yeah, whatever. Look, Kimberly and I have an understanding.”

Jack has seen a good 50 percent of the stock on Eros. He sleeps with older women, mothers and women with overgrown roots. Some months, he pays for their car insurance. He shows me a text from a stripper in Pennsylvania whose TV he hung on the wall for her.

“How about this one?” I asked, pointing to Nikki Irish on the screen. She is older and not Jack’s usual type. “Oh, yeah, Nikki,” he said. “Don’t make that face. What’s great about Nikki is she loves sex. Maybe it’s just sex with me,” he said, winking at Kimberly. “The point is we’ll do it, and then 10 minutes later, she’ll want to do it again, and we’re over her time, and she doesn’t ask for more money. Look, I’m not one of those fools who go to strip clubs and think the girl falls in love with them. But I know when a woman likes sex. And men like women who genuinely like sex.”

On a Monday night at Katelyn’s apartment on the east side, she is wearing a melon-colored shirt and loose jeans, and her blond hair is up in a clip. Her male chef friend is drinking wine and smoking cigarettes at the window.

There is a shoe closet where the spiked Louboutins and the slick yellow YSLs are in labeled bins. “You take care of expensive things,” she said, which is why she charges a high price—twice as much as Kimberly. “The more you charge, the more worth it a man thinks you are.”

On her couch, where most dates begin, she pulls out a three-ring binder that houses a sheaf of spreadsheets, one for each of the 290 men she has known professionally. Here’s a knee surgeon. Here’s a national branding manager. Here’s a diplomat. Here’s a philanthropist. He’s very cool, tall and charming and has a great head of curly hair. He is married and wears traditional suits. There is a cinematographer in his mid to late 30s who likes her in sweats.

There is a section for referrals. There is a slot for “spouse.” A CPL slot, for whether she has been with him and his spouse. A DBL slot, for whether she has been with the man plus one of her fellow escorts.

What he drinks. Where he works. Average meeting length. I tell her about Jack, and she says that, yes, she does have a Jack type. A financier originally from Austin had his friend in from home. They were in the Hamptons, at a house on the beach. They sent a town car at 4 p.m. on a Sunday to pick up Katelyn and her friend Eva, who is an Australian brunette. The rest of the shares had left the house. Katelyn and her friend got there, and there was a note on the door that said, “Go inside. There are envelopes on the table. Have a swim in the ocean; we’re picking up dinner.”

And the girls came in from a swim, shaking off their wet hair on the patio, and the boys were on the deck grilling rib eyes and tongues of eggplant, and they had wine and then dinner, and then they watched television, and afterward, they coupled up and went into separate bedrooms, and there was nothing strange. It was nice. These nice boys from Texas.

“I would date them,” Katelyn said. At around 11, Katelyn’s date, who was high, was in the mood for cookies, so they decided to drive back into Manhattan. They dropped the girls off at Katelyn’s, and Katelyn said to Eva: “Well, a few hours in the Hamptons and cookies. Did we really just make $3,500 to do that?”

Katelyn is sensuous, elegant and smart. Men buy her La Perla lingerie and leave her money in envelopes on coffee tables, and she knows how to dress a roast and when to listen.

When Katelyn is not working, she is working out and reading and dining out with friends and going to London for the weekend and Paris for the week. She is practicing yoga and bettering her body and her mind and advancing her entire being so that she will continue to appreciate in value, in a world where youth is prized over experience and in a city where women will sleep with men for less than Katelyn makes in a minute.

“What women don’t understand is that with married men, their wives don’t listen like I do anymore, and it’s not because they’re bad people. They have children, and they have had 20, 30, 40 years with this man. Boredom sets in. Life sets in. And for the young guys like the man from Austin, he could have sent a town car to pick up any girl he knew in New York. But with me, we can still talk about politics, but I go home and the night is over. Women underestimate the importance of a night being over.”

The level of self-awareness among johns varies. But for most men who sleep with escorts, they’re getting what they need from women without having to give back. If they do something nice for the escort, which many of them do, it’s purely voluntary. There’s a joy in doing nice things when they’re unexpected, like at the beginning of a relationship.

There is, too, the excitement of the secret life. When your friends have gone home to their girlfriends or the girl you’ve gone on a first date with has gone home to dream of your wedding, there is the promise of the evening that follows. “Sometimes, it’s just that I can have this beautiful girl sitting on the couch beside me,” Jack said. “I don’t even want to fuck her necessarily; it’s just nice to know I can reach across and touch her right boob, if I want to.”

The thing is, with Mitchell and Katelyn and Jack and Kimberly, it is an intimate relationship with boundaries. With Katelyn, you pay for a certain amount of time, and you feel for her, and she feels for you—during that time. What she has that Mitchell’s wife doesn’t is the magic switch. “Ideally,” said Mitchell, “you want to have the feeling of making love without having the emotional requirement thereafter.”

Men want to be loving. They want the GFE without the LTR. They want to make love and nibble on lips and watch television and Herbal Essence a woman’s hair in the shower and even tell her that they love her and know she won’t turn it into something else. They feel it in the moment, then they go to work, and the moment stays home, until next time or until they fall in love.

Mitchell has said to Katelyn, “I love you.” She has said it back. Both of them mean it in the moment. But you can’t turn every ride into an odyssey. So you’re Jack, and you are single and disarming, and the world is waiting for you, but you’re not ready. So you sit back on your couch, and you watch the game, and you crack a beer, and you call a girl up, and she comes over in a black turtleneck dress and thigh-highs, or she comes over in sweats. She comes over, and then she leaves, and she leaves more than she comes over.

editorial@observer.com