In her book Full Exposure, sex guru Susie Bright encourages us to redefine the word sex. Sex doesn’t mean just jumping into bed and having an orgasm, she says; sex plays a role in everything from dreams to work to family and friendships. She quotes a friend who claims, “It doesn’t matter whether you’re cooking a meal, or playing a game of basketball, or writing a chapter. Sometimes you get this rush of holistic energy, and you’d swear that you just got laid.”

It may sound a bit much, but there’s some truth to what Ms. Bright says. You don’t need to have sex to be sexy. I myself feel sexy when I’m wearing dark lipstick. I feel sexy when I exercise. When I listen to good music. When I eat at Caf頓eptieme, where the walls are a sexy dark red, the booths deep, and the desserts sinful.

If I think of all the erotic experiences I’ve had in the past week, it would be more stimulating than leafing through the Kama Sutra. For New Year’s Eve weekend, I went to San Francisco to visit my friend Lucy, whom I’ve known since I was 14. Lucy had always been a high achiever, but after graduating from M.I.T. with a degree in chemical engineering, she decided she wanted to do something else. She loved visual art, and when we were in high school, we took the same art class for two years. I remember her final project—it was an oil painting of pointy sperm swimming toward a giant egg. It actually had a graphic-design quality to it; she used only three colors—red, black, and white—and bold, heavy lines. Some people didn’t understand the picture right away, then blushed once they did. Some other students—the mean, snotty ones—just laughed and thought her weird. Now Lucy’s a successful designer for an Internet company.

Lucy’s apartment was small but well kept. She lit some candles, giving the room a warm yellow glow. Lucy is glamorously thin and tall (I always envied that about her), and though she was dressed very casually, she looked sexy. She was wearing stone-washed jeans, black boots, and a fitted tee with the letter H on it. It stood for “Havana,” she said. I told her it reminded me of the hologram character on Red Dwarf, but she didn’t know who that was.

In her bathroom hung a large black-and-white photograph of a short-haired Asian woman with dark sunglasses. She was topless, save for two large sunflowers taped to her breasts. At first I didn’t realize it was Lucy, but then I recognized her slightly crooked smile. It was a stunning, beautiful photograph.

She explained that she had been riding her motorcycle in the Dykes on Bikes parade a few years ago when a photographer friend took that photo. “But you’re not a dyke,” I pointed out.

“They don’t check,” she said.

Later that day, we went to a sushi bar, where we sat next to a tall blond guy from Texas who is now living in Seattle. He was only 23 and had a sweet little twang in his voice. Handsome face, strong jawline. We talked about snowboarding, music, 2000. Every once in a while, I wondered what he would be like in bed. Forceful? Gentle? Would he nibble my ear the way I liked it? Lucy whispered that we should get him up to the apartment and use a dildo on him, making me laugh out loud and choke on my drink. When we got up to leave, he handed us his card. Webmaster, it said. Hmm—so he’s not just a partier.

We never called him—he probably didn’t realize that we’re a lot older than he is. And though it was nice to have the option of calling him, we were having a fine time just by ourselves.