When my wife and I were still relative newlyweds, our friend Gwendolyn stopped by the house one day to change clothes in our closet. Why this was necessary I don’t remember, nor on what trip of hers we were a way station. I also don’t know why she chose to disrobe in the walk-in closet under the living-room stairs, instead of going to the front bedroom or upstairs to the bath. But it made a vivid impression on me.

 Gwendolyn was a knockout blonde, and the wife of the pediatrician for our twin sons. We socialized with her and her husband, including dinners at their country home, where a pack of Newfoundlands ran through the house or bayed in the yard: visitors entered the house between pillars built from 100-pound sacks of dogfood. The food—Gwendolyn’s, not the dogfood—was good and the conversation elevating. As I recall, her parents had been friends of Béla Bartók’s.

 But I had never lusted after her in my heart or anywhere else. Until now, when she was in our closet, peeling down to her undies. Any fantasy or plan of action was short-lived, however. I am many things, but stupid is not one of them. Had I yielded to some errant impulse, Gwendolyn would have decked me and stomped out. Karen would have filed for divorce, and our twins would have lost both their father and a good pediatrician.

 But still, there it was, the image: Gwendolyn, naked or nearly so, in our closet, next to the twin stroller and the foldaway playpen.

 I have thought about this scene over the years, when the conversation has turned to sex. I agree basically with the humorist (Thurber?) who described sex as too fraught with peril to be engaged in by actual men and women. Early in life, this attitude caused me to be regarded by friends as something of an innocent, and I got left out of various male trolling expeditions. My friends probably thought they were protecting me, or saving me (and themselves) from embarrassment. In fact, I wasn’t all that innocent, just mildly repressed in the fashion of 1950s Indiana. I did have some idea of what went on (unlike the mystery of auto mechanics, where I continued to believe that the crankshaft went crosswise with a wheel on each end).

 But sex was pretty much in the imagination, where it flourished and still does. Not long ago, one of those protective friends from youth remarked that he and his housemate, both in their 70s, were getting along fine, although “sex isn’t a big deal any more.” The sex act maybe, I thought, but sex not a big deal? Have you put your funeral director on speed dial yet?

 I did eventually get out of my imagination, but have remained convinced that lurid and hectic sex occurs only in novels and on Dr. Phil. Or that if it does occur in real life, it’s apt to be more comic than cosmic. I’m sustained in this belief by a friend who has written entertainingly about being lured onto a night beach by a fellow partygoer intent on getting both of them out of their clothes and into the ocean . . . for starters. She went first and was attacked by swarms of blackflies, putting a quick end to romance. Also reinforcing my belief are women themselves, who seem to recognize an innocent when they see one, and are invariably friendly, not seductive. There clearly are no pheromones at work here, or if there are any, they’re not working very hard.

Still, there have been curious moments. Years ago, I called at my boss’s house to talk with his wife about something—a charity, I think—and found the foxy Mrs. Boss home alone. We talked business for a few minutes, when the doorbell rang and she stashed me hurriedly in her bedroom upstairs. This struck me as slightly odd—there were plenty of rooms where I would have been out of sight, but the bedroom? Was I in a French farce? It was probably just my imagination in overdrive again. She came back, we finished our talk, and she showed me to the door.

Years later, I found myself alone in Taiwan, where there were plenty of attractive Asian women possibly not averse to spending quality time with someone from the mysterious West, or at least to practicing their English. But loyalty and  innocence (and a certain sense of my own absurdity) came to the rescue again. Peril came instead from an unexpected source—Ohio State University, which had sent a thirty-something intern to the office where I worked. Abigail and I hit it off, ate lunch now and then, and went shopping together. She was chatting cheerfully one day about her underwear and stockings, when I flashed on Abby, stripped, in my apartment, surrounded only by millions of Chinese. I wish I could say that firm resolve and marital fidelity kept me on the right path, but it was more the fear of having nobody to go shopping with.

Ah, the imagination! Gwendolyn is probably a gray grandmother by now. But if she came to my door today and asked to change clothes in the closet, my heart would still go pitty-pat.