It was about 7 p.m. and I was rolling north through the Pacific Coast redwoods with Steve, my occasional significant other. My left hand was squeezing Steve's right thigh. His right hand was squeezing my left thigh. Up ahead, through the sepia-toned windshield, I could see a buttery Northern California sunset. Inside, the car smelled like old shoes, old whiskey, the driver's cologne and my own L'Air du Temps perfume. I was wearing my usual weekend uniform -- tight black stretch pants, boots with stacked heels and a leather jacket. Steve wore old Levi's with the imprint of a can of Bull Durham on the butt pocket and a T-shirt with the name "Southern California Racing Association." We were riding in frowning, concentrated silence.

The feeling began this time just before I told Steve to pull over. I think I said something like, "It's really low, baby. Why don't you stop and have a look?" Steve wheeled onto the shoulder, slipped the gear into neutral, set the brake, got out and slid under the car on his back. I moved over into his seat and gunned the engine. Then he got back in and we resumed our drive. The feeling was very strong now. Steve said, "It's a hole in the muffler," or words to that effect. I said I thought it was the muffler because the sound was too low to be in the engine. Then the sensation really took over, and then, suddenly, I named it. I'm in the wrong movie.

Ever since I turned 45, I've felt an intermittent, dizzying vertigo, as if cameras have suddenly begun to roll on a scene I never rehearsed. And no wonder. I'm supposed to be playing the part of a middle-aged American female. I should be wearing an apron. My cheeks should be plump, my bosom ample, my lap comfortable. I should not be riding around on a Saturday evening in my 49th year, wearing high heels with stretch pants, diagnosing car trouble and squeezing thighs with my date. I should be married to Sammy Osborn from the 10th grade, the boy who aspired to be the weatherman on TV. Sammy would have proposed to me on the front seat of his father's DeSoto, after taking my hand and pointing out cumulus clouds. I would have been married in an indoor ceremony where everyone wore shoes, and our children would spend their summers in New Jersey with their grandparents, eating unhealthy food. I would have a friend named Marjory who sold Tupperware to bring in a few supplemental dollars. As the sun set, Sammy and I would join other couples at the theater or, at worst, the bowling alley. We would have sex on alternate Saturday nights.

Instead, I'm on Take 195 of the epic production "They're Either Married, Gay or Nuts." I stumble through sex and love scenes no middle-aged woman before me has ever faced. Personal ads, tummy tucks, safe sadomasochism techniques for people with arthritis, penile implants and nude weddings. If I should want to meet a guy, I might look for him at the 12-step meeting where my fellow baby boomers gather to reveal our addictions and our histories of molestation and abuse. I belong to a New Age women's spiritual community where I can attend a workshop on masturbation on Saturday afternoon after I see my therapist, where I talk about Steve's efforts to avoid cohabiting with me. No wonder I keep fumbling my lines.

I often get wrong-movie vertigo with Steve. Steve is a construction worker who wears a hunting knife on his belt and races motorcycles on Sunday. He comes from the Irish-Scandinavian-Beach Boys bloodline you see so often in California -- the heritage that produces shaggy coppery hair, high cheekbones, white teeth and commitment phobia. He left high school in the 10th grade and he can pull apart and reassemble my car armed only with a toothpick and a flashlight. I am a college-educated, urban-bred New Englander of Russian descent. Steve spends two nights a week with me -- Mondays and Fridays. We share fast food, raucous sex and the television. He keeps one pair of white jockey shorts, one pair of wool socks and a towel at my house, a migration of belongings that has taken four years. He came in last Friday after work carrying a medium combination pizza in a cardboard box. I was wearing my bathrobe and slippers and I was still warm and damp from a visit with Luanne from the office.

"Hey, baby," he said. "You just get in? What've you been up to?"

"Oh, God, it was perfect," I said, toweling my hair. "Luanne and I were both wiped out after the board meeting. It went on forever. So afterward we went over to her place, got in the hot tub out on her deck and talked shop."

"Did she have a good look at your clam?"

(I glanced around wildly for the cue cards.) "She isn't interested in my clam -- I mean, my vagina. Jesus, Steve. Just because we were naked doesn't mean we, you know, did anything."

"Didn't you tell me Luanne is a dyke?"

"She is a dyke. Don't use that word. She is gay. But that doesn't mean she wants to hit on me. Do you check out every woman you see just because you're heterosexual and they're women?"

"Yeah."

Private Life Romance, relationships, and the personal side of Table Talk