Maybe it was always within me. Maybe it was after I found it so difficult to make friends with girls my own age. Maybe it was when I looked on from afar at how wonderful I found the girls' little pleated skirts, with the thrill of a possible glimpse of their knickers.
However it was, when I found myself having Wednesday afternoons off and being home on my own, I couldn't help myself but venture into my little sister's room and explore her clothes.
It didn't take long before I found her knicker drawer. Amongst the frillies and plain cotton knickers I soon found what I was looking for - her gym knickers.
I held the bottle green nylon knickers up against myself, and knew I had to try them on. I went back to my room and stripped naked. Then I went back into her room and grasped her gym knickers.
The feeling of putting them on was exquisite. Next I put on one of her aertex blouses, and finally I found her spare gym skirt. It was very short, pleated, and I felt a wave of pleasure sweep over me as I fastened it round my waist.
I pranced around her room, delighting in how 'my' knickers were revealed when I bent over.
I found a pair of her white knee length socks and put them on too. I felt SO girly.
Then I went and sat at my desk doing my homework, pretending to be a little schoolgirl.
I knew my mother would be home at five o'clock, so at four thirty I reluctantly took off my sister's clothes and put them back where I'd found them.
With my heart in my mouth I waited until my mother and sister got home. But they didn't notice anything amiss, and I was delighted to have got away with dressing as a little schoolgirl.
I couldn't wait until the following Wednesday...