I was gazing into J. Lo’s brown eyes. We were inches away from each other, locked in an even gaze, her face tilted up slightly toward mine. I could smell her hair spray. Then the director called, “Cut!”

It was the summer of 2016, and I was acting in an episode of an NBC crime drama called “Shades of Blue.” I use the term “acting” loosely because I had exactly one line.

I had never watched “Shades of Blue” before I tried out for it. All I knew was that it was a cop show set in New York City starring Jennifer Lopez and Ray Liotta. To be honest, I thought of the role as a potential stopgap at a time when I was in a figuring-things-out phase of my life. Although I had appeared on a soap opera years earlier, since its cancellation I had mostly checked out of the audition circuit.

The audition was held in an office building in Midtown. The casting director, Rob, had me read for three roles: “F.B.I. Commander,” “Bailiff” and (horrifyingly) “Old Cop.”

Before I left, Rob told me: “Look, if you get one of these, just be cool, OK? Be cool.”

There were no callbacks. I was hired for the part of “Bailiff.” My duties consisted of asking a character named Harlee, “Do you swear to tell the truth, the whole truth and nothing but the truth, so help you God?”

Once I got the part, I Googled “Harlee on ‘Shades of Blue’” and gasped. Harlee was played by Jennifer Lopez. This sent my imagination off the deep end, as I briefly entertained the notion of bonding with Jenny from the Block. I thought of all the things I could say to her: You were terrific in “Selena.” I cried at the end of “Maid in Manhattan.” You never should have been with Marc Anthony anyway!

Then I stopped myself. I was hired for a job. I was a professional. I was going to be cool. Besides, even small TV jobs were hard to get, and I was determined not to mess this one up.

The shoot took place at the Bronx County Courthouse. When I got there, I put on my assigned uniform and was ushered into a courtroom for rehearsal. I met the actor playing the judge and a young woman who was Ms. Lopez’s stand-in. Before I could ask her name, I was distracted by the props guy, who pulled me aside and pinned a badge on my uniform. Then he handed me a Bible, and the director called, “Places!”

I returned to my spot in front of the courtroom. A buzz swept through the background actors playing spectators in the courtroom. In a moment, I was face to face with my scene partner. She smiled, extended her hand and said, “Hi, I’m Jennifer.”

I nodded and shook her hand. I felt like an idiot, because I couldn’t verbalize a simple greeting. Then the director started rehearsal. I held out the Bible and we did a run-through.

The star of the scene was not me or even Ms. Lopez. It was her left hand, which she placed on the Bible. This gesture had its own close-up, and the director spent much time making sure he got the shot.

“Raul, can you raise the Bible? Great. Now, er, Raul, can you lower it a bit? Great.”

Again and again, a woman tended to J. Lo, applying makeup, lotion and a nail spray. My hand was perspiring, and my arm was cramping from holding the Bible in place. We spent well over an hour on this shot.

Perhaps because she had heard the director shouting my name from across the set, Ms. Lopez glanced at my name tag, which read “Smith.”

“Oh, that’s not you, right?” she asked with a laugh.

I shook my head. I still wanted to introduce myself, or speak actual words like a normal person, but I couldn’t.

“Ha-ha, that’s funny,” she said.

Then a small army of hair and makeup personnel helped get her camera-ready. They fussed over her, like bees swarming a hive. She had one makeup artist whose sole responsibility seemed to be her lashes.

During a break, a young production assistant mentioned that the day was going well, because there were no fans or paparazzi lurking outside the courthouse.

“We don’t list Jennifer on the call sheet,” she said, “because it might get leaked, and then we have to shoo off these weirdos.”

At lunchtime, the cast and crew ate in the courthouse basement. Although the atmosphere was convivial, I was annoyed at myself for having been so flustered in J. Lo’s presence. I was fine once the cameras were rolling. It was only when I had to engage as a real person that I was inept. I resolved to be cool around her in the afternoon.

After lunch, we continued the courtroom scene, where Harlee took the stand and was cross-examined by a handsome prosecutor. Their dialogue crackled. Envious of their rapport, for a second I wished I had his part.

Later, as the cameras were being repositioned, Ms. Lopez, the actor playing the judge and I sat down on canvas chairs in a nearby hallway. The judge asked J. Lo for a selfie, and she obliged.

I pulled out my book. Next to me, Jennifer was texting and conferring with an assistant. It was warm in the hallway, because the building’s air-conditioning had been shut off for shooting. I tugged at my collar. Jennifer looked over and asked, “What are you reading?” Once again unable to speak, I held out the book, showing the title. “Nice!” she said.

Right then, I could’ve punched myself. I was probably one of the few people she had encountered who acted aloof with her. What was wrong with me?

As I was leaving at the end of the day, I passed her and her assistant as they were walking back to their trailer.

“Thank you,” I managed to say.

“Bye!” she said.

When the episode aired, it was titled “Eye of the Hurricane.” The courtroom scene was interspersed with steamy shots of Harlee in bed with the handsome prosecutor. I was only briefly on camera, in a single wide shot. My line was practically a voice-over. J. Lo’s hand looked great.

Raul A. Reyes is a contributor to NBC Latino and CNN Opinion.