That day I didn't dare pull the blanket from me to reveal myself fully - that landmark in my sexual development came a few years later. I was a student in my first year at university, virginal and shy. I had had a sheltered upbringing and so, while in retrospect I can see I adapted and matured very quickly, at the time I felt gauche and inferior in comparison to my more experienced friends.

It was a particularly fine day, I guess at the end of September or early October, one of those days when autumn forgets itself and mimics the gentle promise of spring, with fresh sun and warm breeze and gentle, vivid air. I had taken myself out for a drive, investigating the craggy countryside. Avril, who had the room next to mine in our six bedroom student flat, had brought a man home the previous evening, and I discovered for the first time how thin the walls were. The sounds of their lovemaking had gone on into the early hours and I lay next door, frustrated and curious, desperate for knowledge. Listening intently, I stroked my slit in rhythm with the lovers next door, but didn't dare take myself to climax for fear of letting out a moan and alerting people to what I was doing. I can laugh now, but at the time I didn't see any incongruity in my reticence.

And so, the next day, I was still feeling aroused and dissatisfied. As I drove I pressed my hand over my crotch, pushing my palm over my clitoris. I could feel the excitement filter through my body, raising my nipples erect and sensitive, flushing my face and neck and tingling down my arms and thighs. In my distracted state I feared I was becoming something of a traffic hazard and pulled over into the next layby.

I was highly sexually charged, and yet very inexperienced. I think that was a factor in what I did next: I had so much excitement running through my body I had to release it somehow and, not having experience of more conventional methods, invented my own. My initial thought was that I was going to masturbate in the car, bring myself off so I could continue with my drive unaffected by libidinous overload. There were lots of cars and lorries passing, however, and it felt impractical and unsatisfying. I had parked next to a wooded area, dark and secluded and somehow the thought entered my head to go there to conduct my solo lovemaking. It'd be quieter and more sheltered than doing it in the car, I thought.

As soon as the idea entered my head it took over. My excitement doubled, trebled, my body trembling at the thought of masturbating outdoors. Although my first thought had been that the woods would offer more privacy than my car, it was the notion of being outdoors, in the open, which really galvanised me. I got out of the car and jumped over the crumbling wall into the wood. It was overgrown and unkempt, broken branches and the crumbly, fragrant residue of several years fallen growth scattered over the ground. I scrabbled through, fighting against increasingly dense undergrowth, beginning to regret my decision and trying to convince myself that I wouldn't do what I had set out to.

But I knew I would.

As I walked on, deeper into the wood, I stroked myself through my jeans. I was tingling with anticipation, imagining playing with myself while sitting in the open woods. I undid my button and slid the zip down, feeling the air against my panties. With my hand pressed against my mons, fingers sliding across my slit, feeling my lips swell beneath the cotton of my panties, I walked on determinedly. My initial thought had simply been to find a broken tree to sit on while I frigged myself, but I was growing more horny with every step.

I'm going to strip, I thought. Completely naked.

I conducted an argument in my head, alternately convincing myself that I would indeed go through with it and that there was no need to worry because I would never do anything so foolish. Deep down, though, I think I knew what would happen, I think I knew which argument would prevail.

I came to a clearing. There was a big, fallen tree resting across it, offering a perfect perch. I looked around. Nothing, no noise but for the rustle of the remaining leaves and the solitary cries of a couple of birds. If I was going to do it, this would be the place. Negotiating with myself, I tried to reach a decision, all the while resting on the tree and pressing my palm against my clitoris. Quietly, I slid my jeans over my bum and dropped them to my knees. Unrestricted, I could now part my legs and settle my fingers against my slit. It was soaked, my juices oozing into my panties. I wanted to take them off, to reveal myself to the world. Looking round, feeling very exposed, I raised myself from the tree trunk and slid my panties down, gasping as the cool wind drew across my pussy lips for the first time.

My body began to respond as I stroked up and down my lips and played my thumb around my clitoris. I became flushed and aroused, quickly losing sight of common-sense. I wanted to be naked. I wanted to be exposed. Looking through the clearing once more, I gripped my tee shirt and raised it over my head. The coolness of the wind against my skin was electrifying. Reaching behind, I unclasped my bra and let it fall to the ground, and instantly my nipples swelled more stiffly than I had ever experienced. They were almost painfully erect, my puckered areolae enhancing the effect and making my nipples appear to stick out much further than ever before. By now I was concentrating almost exclusively on my clitoris, stroking my index finger round and round, dragging the nail against it, squeezing it between thumb and middle finger.

I stood up. This was the moment of no return. I knew now that I would go through with it, that within moments I would be completely naked. I undid my shoes and heaved them off, followed by my socks. Stopping for one final - and by now pointless - look around the clearing, I slid my jeans and panties down and stepped out of them.

I was totally naked.

An overwhelming rush of sexual arousal flew through my veins and nerves, leaving me gasping. I was senseless by now, overcome by the knowledge that I was completely naked, outdoors, and that anyone could see me. Somehow, it didn't seem enough: I wasn't exposed enough, because my clothes were at hand. If someone were to come I could make myself decent relatively quickly, and that wasn't good enough. I was coming to understand the nature of my exhibitionism.

Picking my way gingerly over the rough ground, I walked to the far end of the clearing, away from my clothes, away from safety. The air against my skin was delicious, each gust of wind adding a frisson of excitement. Some thirty yards from where I had undressed I stopped and leaned against an old oak, bending and sitting on my haunches, legs spread wide. I closed my eyes and pressed my thumb hard to my clitoris, stroking my fingers furiously against my engorged lips. I began to moan and scream as an extraordinary set of reverberations, vibrations and whirling, whorling eddies began in my belly and womb and alighted across my arms, legs, fingers, toes, bursting through my head and hijacking my brain with visions of ecstasy and notions of lust.

My climax came, my body ripped asunder by wave after wave, my skin alive with lust. I continued to stroke myself gingerly, forgoing my now too-sensitive clitoris and sliding against the sticky moistness of my lips. I opened my eyes.

And saw a man.

He was old, around fifty, I guess. He was watching me intently, making no attempt to conceal himself. I screamed and jumped up, my nakedness no longer an exciting indulgence but a fearful, humiliating encumbrance. The man appeared startled by my sudden movement and backed away. Stopping for one final look he turned - reluctantly I fancied - and walked away.

But it was too late. I knew I should have felt ashamed. I knew that it should have taught me a lesson. But I also knew, deep in my soul, that what had occurred was the most exciting thing I had ever encountered. I had been caught, and I loved it.