"I don't believe in sluts."

Sitting behind me, in the back of my taxi, the man proclaimed his views on the evolving issue of promiscuity. I say "evolving," because not very long ago societal opinion was fixed and harsh: Girls who slept around were branded "sluts," while guys got a pass or even were glorified as "ladies' men" or "studs." Lately, I've heard men also being referred to as sluts, so that's progress, I guess.

"Jason, you loser," said the woman sitting beside him, "it's not a matter of belief. Donna's been with, like, every guy we know. I love the girl, but face facts - the woman is a slut."

We were driving south on Route 7, en route to Hullcrest Road in Shelburne. Discreetly, I reached down and lowered the volume on the radio. This couple's sociological debate was compelling and funny; I wanted to catch every word - the full dialectic, as it were.

"OK, OK," Jason shot back. "Lemme put it this way, Karen." He edged forward in his seat for extra effect. "Let's say I'm hanging with a hot 28-, 29-year-old, and she's been with, say, 50 guys. Well, you better believe I'm hoping to be number 51!"

Karen laughed and said, "Excuse me there, buddy boy, but you ain't 'hanging' with any hot 29-year-olds. You my man and don't you forget that!"

In the rearview, I saw Jason smile broadly. He liked being Karen's man. Then he said, "Brian, why don't you weigh in on this? What do you say?"

Up till this point, the man sitting next to me in the shotgun seat had been completely quiet. I could tell he was following the couple's snappy repartee, but only vaguely.

Now Brian pivoted in his seat and said, "Jason, you're my big brother, so I can't be exactly objective about this, but I gotta agree with Karen: Donna's a slut - and, by the way, so are you."

Jason reached over the seat in mock outrage and cuffed his brother on the head. As all three of them laughed, Karen said, "Right on, Brian. That's what I'm talking about. Sure Jason doesn't believe in sluts - that's 'cause he is one!"

"Hey, Karen," Jason said, turning to face his girlfriend. "Isn't Donna now seeing Jeffrey? Did she talk to you about him? We want the sex details."

"Are you high? Donna doesn't talk to me about that. What do you think - we're, like, guys? Girls don't give details like that."

Jason said, "Well, I'm not sure I'm buying that. I think you're holding out on us."

As we took the left onto Hullcrest, I asked, "So, you guys all live in Shelburne?"

"Karen and I do," Jason replied.

"How about you?" I asked my seatmate.

Brian paused for a moment, then said quietly, "I live in London."

"Well, that's cool," I said. "Work brought you there?"

"Yeah."

"Brian's in the military," Jason piped up from the back.

We arrived at their destination, and I told them, "For the three of you, that'll be 12 bucks."

Jason said, "No, just me and my girlfriend are getting out here. My brother's staying with our folks in Shelburne Village."

The couple paid up and left, and Brian and I drove down the hill and back onto Shelburne Road. As we passed the Volvo dealership, I really looked at Brian for the first time, noticing his military buzz cut and crisp, rolled-up blue jeans. I asked, "So, what branch of the service are you in?"

"I'm in the Air Force."

"Stationed in England, huh? I guess you're not seeing action in Iraq?"

"Are you kidding? I've had two tours. I'm just on leave now, and then they'll send me back."

"What's it like?"

"The hardest part is the first week when you get there. All night long, you hear the exploding mortars. It's, like, impossible to sleep. Then, when you leave, you go through Qatar. They have you spend like a week there. Depressurizing, I guess, is the idea."

"It must be great being back in Vermont for a while."

"Oh, yeah - it's great," Brian answered, none too convincingly. "Yeah, I've been having a blast, hanging out with my brother, going out at night."

We rode in silence for a couple minutes, and then he added, "I actually haven't slept at all for the week I've been back."

"Jeez, that must be tough," I said - trying to be empathetic, though I had no personal frame of reference to help me understand what this guy was living through. Not even close. I glanced over again and saw a Vermont kid, couldn't be more than 23, 24 at the oldest, his mental health already compromised. God knows the state of his soul.

"I think," Brian said, "I've gotten too used to the mortars."