Around 3:30 on a recent morning, I opened my eyes and found myself in the burgundy comfy chair I had plopped into in our darkened den just an hour before. I had sought refuge from the relentless pounding that helps define rap music. It had been drifting up from the basement for a few hours, ever since my son and 15 of his classmates returned from the junior prom, eager to begin their all-night post-prom party.

They were an exhilarated bunch, arriving with smiles and high-fives, and offering bear hugs to all. All of this, I figured, meant that they had fun. Still the father that I have become, spoke. “How was it?’’ I asked Aaron, my 17-year-old son.

This was the first formal dance he had chosen to attend, and hours before he had taken great care to make sure his rented tuxedo was spotless and his carnation was pinned properly. Now, he was tearing off the tux, tossing it on his bed, all the while texting a friend and changing into jeans and a T-shirt.

“Good,’’ he said, with a big grin. “How you doing?’’

There had been little planning for the party, just like there had been almost no discussion about it when Aaron asked whether he could host his friends. Devorah and I shrugged and said sure — in almost the same way we had agreed to his numerous sleepovers when he was a child. This time, though, would be different. For a few short hours, I would be more than a dad. I would be the house cop, a position I am ill-suited to fill.

We agreed to the party in almost the same way we had agreed to his numerous sleepovers when he was a child. This time, though, would be different. I would be more than a dad. I would be the house cop, a position I am ill-suited to fill.

Weeks earlier, I had attended a short prom primer delivered by the superintendent of our town’s school district. He told the assembled students and parents that his greatest fear was what happens after the party. The prom, where students would be escorted by buses to and from the event, and where they would be subject to random breathalyzer tests, would be well supervised. The horrors could occur after the event, when students are left on their own, he told us.

The idea of having a bunch of kids in my house was comforting and suddenly daunting. After some thought, I gathered a list of cellphone numbers for all of the kids’ parents, and wrote out ground rules, which Aaron eventually posted on a Facebook page.

“No alcohol, drugs, sex, or really loud music, and no leaving the party once they're here,’’ I told Aaron.

“Sure,’’ he said.

I had expected a longer conversation, but a lot of what you think will happen when you talk to your child never occurs.

Just before midnight, all 16 were in full-party mode in our basement. For decorations, Aaron had set up streamers and had spelled the word “PROM’’ in thin, red paper on the paneled wall. Two of his disc jockey friends had set up a stereo system — loud enough for a block party, but in this case, turned low enough that I could barely hear it when I went outside and stood across the street.

It is a quiet neighborhood, and after midnight few people drive on the road. As I stood there, I recalled images of my junior prom. There was little fanfare about the dance in 1976, when I escorted a girl I barely knew to it. She was the daughter of close friends of my parents, and our union — at least for one night, over chicken and some dancing — had their approval. My sister drove us to the prom, held in an Italian-American hall, and when it was over she dropped off my date at her house in Chelsea.

Heading back inside, I took my time walking up the stairs and then went down to the basement. No smoke. No signs of alcohol. Just a bunch of kids talking loudly over the music and eating pizza. A couple of boys even thanked me for inviting them over, and promised that everyone would be on their best behavior.

They’re all 17, but the mood and their smiles reflected a much younger bunch. This scene, I realized, had been played out at birthday parties, sleepovers, group trips, and class visits. The dynamic would never change: I would always be a parent, and they would always be kids in the process of growing up.

Soon I was headed toward the comfy chair where I would, no doubt, put all of this in perspective. I sighed and closed my eyes. Youth, I realized, is only understood by those experiencing it. But the energy and hope that forms when teens trust one another and dance and talk loudly is palpable, and a little of that optimism found its way toward me.

When I awoke, I went down to the foot of the stairs. There was silence, except for some snoring.