My freshman year at Lewis & Clark College—a glorious hippie wonderland—I dated this little flower child named Kristen. Not her real name. What I liked most about Kristen was that she lived down the hall from me. If she'd moved to the other side of the dorm, I'm pretty sure that would have been the end of us. Profoundly earnest, Kristen had a narrow avian face and a fragile little sparrow chest. Listening to me, she'd tilt her head and bunch her mouth, as if rapt, but her wide blinking pigeon eyes revealed emptiness inside.

Once, at the end of winter break, a bunch of us friends arrived back to Portland on the same day. Kristen's friend Tara, a proto–Nicole Richie (a blond SoCal girl with a lot of money and a flair for hedonism nicely undercut by her taste for new age mumbo jumbo)—well, Tara had a hotel room at the posh Heathman Hotel. She invited us over. So Kristen, our friend Greg, and I stayed the night with her.

Droopy with Xanax and red wine, the four of us ended up in an awkward orgyish situation. Kristen and I were on one side of the bed, and Greg and Tara—not a couple—were on the other. Occasionally, I'd reach across the bed and grab Tara's breast, or Greg would reach for Kristen's delicate thorax. After Greg ejaculated very memorably across Tara's milky abdomen, we turned out the lights and passed out.

Except that I was in the middle of the bed. And Tara was in the middle, too, facing me.

Now, to be clear: I was just 19. And I was a terrible person. Or, if not terrible, I was certainly not equipped with a very steady moral compass. Like many young men, I'd spent a lot of my adolescence masturbating to imaginary sexual scenarios, so whenever actual sexual scenarios emerged, I was ready to go.

Nowadays, I'm mostly weary. I love sex, obviously, but I've got young kids—I probably have barf on my shirt as I sit here typing. When I watch Louis C.K. do standup, I don't even laugh, I just grip my forehead with both hands and say, "Oh my God... oh no... oh my God... oh no..." Every single word seems to spring directly from my own rotten id.

But in that hotel in January 1997, I looked like a young Ralph Macchio and was as pervy as Portnoy. So Tara and I quietly and discreetly—flanked by my sleeping girlfriend and my best friend—pushed our pelvises together, slow and subtle as possible. Sex, per se, was a logistical impossibility, but what happened instead was what sex is at its very best: trapped at the border of paradise, shuddering for breath. It was one of the most sexually exciting things I'd ever experienced, and I had by that point experienced quite a few sexually exciting things.

The following morning, the four of us verbally revised and sanitized our shared memories.

Three weeks later, wasted on tequila at a party on campus, Tara pulled me aside, eyes blazing, and whispered, "Why haven't you come and fucked me yet?"

Kristen was on the far side of the room.

"That's an excellent question," I said.

I followed her out into the night. We arrived at her dorm room a few minutes later, and she barricaded the door against her roommate Christina, another of our close friends. Half an hour later, Christina was pounding on the door. She speculated loudly about who Tara might have inside. Petrified and giggling, we hid under the blankets until she finally gave up and left us in peace.

A few months later, over spring break, a bunch of us went to New York, and we stayed at Christina's family's place in Park Slope. On the first night, I slept with Kristen. After all, she was my girlfriend—it would have been unseemly to not have sex with her. On the second night, after Kristen was asleep, I went over and visited Tara. On the third night, after Kristen was asleep, I went over and slipped into the bed of another of her close friends, Greta, who I'd started sleeping with also.

Then all the other girls left town, and it was just Christina and me on the final night.

"You are a terrible, terrible person," Christina said. "Did you sleep with Tara this weekend, too?"

"No," I said, nodding Yes.

"Jesus, that is so cold. What about Greta?"

I grimaced. "That would be awful, wouldn't it?"

"No, not awful. It's just gross."

I nodded.

"It's like—it's actually disgusting," she elaborated.

"I know." I sighed. Then, after a beat, I said, "So I guess there's no point in me asking..." I winced.

"OH MY GOD! Are you fucking kidding!" She burst out laughing. "Are you insane?"

"No, no, I didn't mean it," I said as unconvincingly as possible.

"You're fucking insane."

Later that night, we went to the 7-Eleven together to buy the condoms.

A month later, Kristen found out about one of the many times I'd slept with Greta. She was understandably distraught. I apologized, and we made up. By then I was also occasionally sleeping with her friends Priya, Wendy, and another woman whose name escapes me.

That summer, I called Kristen up and claimed to have fallen in love with someone else, which wasn't true. She wanted to know what this girl had that she didn't have. "I don't know," I muttered, trying to imagine this fictitious girlfriend of mine, "she's perfect for me."

Three years later, after we all graduated from college, Christina and I slept together once again. There was new chemistry between us, a couple old friends. We moved in together in Seattle. With saved money from our first day jobs, we went to Italy and Iceland, and I believed for almost a month that we were in love. But living together was a lot like matrimony, and I wasn't in a marrying mood. Though legendarily promiscuous, I thought I was just hitting my stride.

So one day, I came home and told her I'd bought a one-way ticket out of the country. Which was true, actually.

"You're such a fucking bastard," she said, and I knew that was true, too, it had always been true. "What is your problem?"

"I'm an idiot?" I offered.

"No, you're not an idiot." Beneath her fury, she was genuinely perplexed.

"I don't know then. Maybe I'm just an asshole."

She frowned, nodding. "I guess that's it. You're just an asshole."

A dozen years have passed, and none of us are friends anymore. But we're all friends. We'd meet for a drink, if circumstances permitted. There would be no hanky-panky, though. We're all too diminished for that.

Kristen married a handsome little guy; in photos, they look like normal-sized people. Tara lives in Los Angeles, and on Facebook, where she poses beside emaciated celebrities, looks sincerely happy. Greg has twice married, with kids by each wife. I look back on that time, when I was 19 and indulged in so much wanton ravaging of that circle of friends. I think of my total indifference to anyone else's feelings, the lies I told, and I know it doesn't speak well of me, but the fact is, I'm glad I did it.

Now, though, I'm just weary. It's not that I don't lust after random or not-random women, but I've had a lot of sex—I can maybe remember half of the women I've slept with—so I don't feel the same urge to go "conquering" anymore. Or, I feel that urge, but the work involved... Plus, I have, in my advanced age, developed a slightly more nuanced sense of right and wrong, and I wouldn't do that to my wife. I don't even want her mixed up in this confession, so it's being published anonymously.

Sometimes she worries that I'll get bored of our quaint life in Ballard: pajamas at 7 p.m., reading the New Yorker to each other while doing dishes, arguing about the garden. Of course not, I tell her. I know what's out there. I've picked over the bones. I know the work, and I know the reward—I know better than anyone.