I was fifteen, and he was in his twenties.

I wasn’t coerced, though. I wasn’t tricked or manipulated. I said yes—said it freely—because I wanted something. I wanted sex—or whatever it was that happened between two men. Of course, I wasn’t a man yet.

When I think back on this, I wonder if I can trust my yes, the yes of a child. My body says that I can, but maybe I can’t trust my body to work this out.

I hadn’t thought about the man in a while; my time with him was more than thirty years ago. But lately his ghost has returned—maybe in light of the current debates about sex and power. These conversations have got under my skin, like a virus, making me sick with questions I’d never asked before: Was I manipulated? Was there an imbalance of power?

It’s entirely plausible. I was a small, skinny guy who self-identified as weak, and so shy that I could barely speak in social situations. Often, when required to interact with strangers, I would begin to shake, in a frightening, fit-like manner.

The man—let’s call him Sam—was quite the opposite: muscular, steady, confident, a lifeguard at the beach where I sometimes went with my parents. I had seen him a few times, certain he’d never noticed me. The day of our first encounter, I watched from a short distance as he taught a class to teen-agers—lifeguards in training, I suppose. The students were putting their mouths against a dummy.

I wasn’t old enough to participate; to be a lifeguard, you had to be at least sixteen. And surely you needed more than golf balls for biceps—which, along with freakish, flagpole legs, were the sum of my physique.

Later that day, I saw him again, leaning against his scaffolded throne, eating a nectarine. He caught me looking, and then he was walking toward me. I stared at my feet.

“You were in my class, right?” I heard him say.

“No,” I muttered. “I was just watching.”

When I glanced up, he nodded—and immediately I felt my cheeks burning. Did he know what I’d been watching? His bare chest and tanned legs, the snug black Speedo.

I was trembling by that point, but for some reason when he said, “Walk with me,” I followed him.

For a few minutes, we didn’t talk—which both disturbed and excited me. Our silence seemed to suggest that we agreed on something. It was like a pact.

I followed him to a more deserted part of the beach, and then we were walking away from the ocean, toward some scrubby hills. I reminded myself that a lifeguard was like a policeman—a person you could trust.

“Are you O.K.?” he asked, noticing my jitters, or perhaps hearing how my teeth were chattering in spite of the scorching August sun.

When he finally stopped and turned toward me, we were in a patch of shade, surrounded by larger bushes and even some trees. If my mind said run, my body argued stay. I was locked in place by confusion and desire and a slow-reeling vertigo.

He asked why I was standing so far away.

I shrugged, and when I made a move to leave he approached, and touched my arm. “Don’t.”

He wasn’t rough; he smiled. I could see the blond stubble on his golden chin. His beauty was formidable.

I said that I should probably go, while, below, my arousal contradicted me. He noticed, and drew my attention to the fact that he was experiencing a similar “problem.” As we made small talk—the weather, the waves, my sunburn—the real conversation seemed to be happening between our bathing suits.

Somehow, a few minutes later, we were naked, with our hands going exactly where hands shouldn’t go—or exactly where they should. I was in a limbo, in which there seemed to be no difference between the forbidden and the necessary. The sense of inevitability, of falling, was profound.

I had been with girls before, but we’d only kissed—and never with our clothes off. And those experiences had always felt like rehearsals for desire, ones in which I played my part perhaps too fervently, knowing that I’d been miscast.

But now, as I followed the lifeguard’s lead, I felt that he was pulling me closer to myself. Strangely, this did not feel safe; it felt like drowning.

And then we were both lying on the sand, soaked and winded. For a moment, we stayed knotted together, as if untangling ourselves might prove to be too much effort, or leave too much room for questions and regret.

Finally, I slid away, and as I put on my bathing suit I felt a need to defend myself. I told the man I’d never done anything like that before.

“Me neither,” he said.

I didn’t believe him—he looked like a movie star. But maybe he meant he’d done it only with girls.

When I asked for his name, he told me.

He didn’t ask for mine, and I thought, I’ll never see him again.

But, as I turned to leave, he took a notebook from his backpack and wrote down a number.

“Call me,” he said. “O.K.?”

At home, I put the number in a case meant for hiding keys—a tiny magnetized box that fit perfectly, and nearly invisibly, behind the metal desk in my bedroom. I’d bought the case a year before, liking the idea of it, but until now I had nothing to hide apart from a few wheat pennies my grandmother had given me.

Summer was over, and I was back in school, feeling as I often did this time of year: anxious and beleaguered. School brought out the worst of my stutters and shakes, driving my unnaturally high voice a notch higher. I mostly kept quiet, with my head down, fearful of bullies.

Unexpectedly, I felt no real shame about what I’d done with the man. On the contrary, the memory of our encounter often made me smile. What had originally felt like drowning now felt like flying. I was suddenly above myself—not at all the person I’d thought I was. My secret somehow invigorated me.

Of course, I was still incredibly insecure, which was the reason I hadn’t yet called the man. I just couldn’t understand why he’d be interested in someone like me. Hadn’t he seen my girlish legs, the spots on my cheek? I found myself wondering if the whole thing was some kind of trick. Maybe what was really going on was a plot to humiliate me. Maybe, if I met him again, my parents would be there—or possibly the press, snapping photos. I’d be on the front page of the local paper, exposed. As a secret, my deed held no shame, but I was terrified of the judgment of others.

When I finally dialed Sam’s number, my stupid teeth were chattering again. Miraculously, he remembered me. He was whispering, saying he couldn’t talk for long. When I found out where he lived—nearly an hour away—my heart sank. But then he suggested that he drive to where I was.

“You can’t come here,” I said—whispering, too.