Here's a story I wrote awhile ago:

We're on a cross-country road trip, going through one of many long, flat, empty Midwest expanses. The night is still young and there are a few hundred miles between us and our next stopping point. I know you'll take me from every direction once we get to the motel, but that's a few hours off and I'm horny NOW. I'm wearing a knee-length skirt (much more comfortable for traveling than pants) and my hand mindlessly wanders under the hem as I start stroking my thigh. You're still mesmerized by the road and don't notice, and I wonder if I should just get myself off while you drive. My always perky tits are getting hard and I give one a little squeeze. God, I'm horny. I'm not wearing a bra and The Girls look ready to bust a hole in my shirt. Another little squeeze and I let out a muffled noise.
"You ok?" you ask, eyes still glued to the road.
"Yeah," I say, voice strained with the sudden realization that I need to have you NOW. You flash me an unknowing smile, thinking I'm just restless from the car, and that's all I can take. I put my hand on your thigh and you smile again, placing your strong hand on mine. I move my thumb back and forth, simultaneously tickling your palm and thigh, inching upward all the while. Your face is still steely, eyes fixed on the road, but the warm bulge in your pants, straining to meet my strokes, gives you away in a heartbeat. My left hand continuing its little caressing journey as my right comes over to undo your fly. You feel my hot breath as I lean over and I kiss your neck, sweetly at first but with a naughty nibble as your hardness springs free from your now opened pants. You gasp as I giggle, moving your boxers out of the way so I can wrap my hands around your beautiful cock.
I start slowly, tracing the veins and creases with my little finger and the lightest touch. Desperate for more, you try to move your right hand in (left still on the wheel), but I catch it and start kissing and sucking your fingers as I go from tracing to pumping your glorious stiffness. I release your hand so I can use both of mine in quick succession to treat your member to a constant pulling, milking, begging for release. You run the fingers of your free hand through my hair and urge my head towards your lap. How can I refuse?
I pop just the head between my lips and deftly tongue the tip while still stroking the base with my hands. I dig deeper into your pants and you lift up just enough to give me access to your balls, which are swollen and full and begging to shoot. As I cup them in my warm dainty hand I begin running my tongue in circles all around the head of your cock. I’m tonguing and sucking for all I’m worth when suddenly a bump in the road forces you deep into my throat. I gag at first, jumping back to release you completely, but I immediately drop all the way back down, taking you all in, still tugging at your testicles. We must be on a bad stretch of road because the car is bouncing and my mouth is trying to keep sucking you all in and I can barely keep hold so I suck harder and deeper and just when I think I can’t stay on like this much longer I feel you stiffen and moan as load after load of hot, sticky cum shoots down my throat. I swallow and swallow (I wouldn’t want to mess up the upholstery, now would I?) and you’re making this incredible gasping noise and we’re still moving as I milk you clean and dry.
I sit up and smile at you as you wipe off my mouth with your thumb and I give it an impish bite.
“Wow,” is all you can say.
“You owe me when we get to the motel,” is my half-giggled response.
It’s now that I notice we’ve pulled off onto a dirt road (explains the earlier turbulence) and with nothing but corn in sight for miles you stop and turn off the car...