When Juli Patterson came to work for my mum that summer she was 28. The day she first touched me, it was a few weeks after my 18th birthday.

She was studying teaching part time and needed extra money. One of the good things about the cleaning job was that she was paid cash in hand and didn't have to declare it. She'd worked for a few years as a hairdresser but hated it; the teaching course was an attempt to better herself, a chance for her to have a different kind of life.

To me, 28 seemed not ancient but certainly incredibly mature. I wasn't interested in her past or what she wanted from life. I only found out those details later. At the time they meant nothing to me. What I wanted to discover was what kind of sexual experience she'd had. I wanted to benefit directly from that knowledge.

As I lay in bed the night of the party, for the second time since she'd lain in it, I could still smell her on the sheets. She filled my mind, pushing every trace of Becky Sidcup away. It was amazing to me that her smell could be so lingering and I wondered how many nights it would stay. Until the next wash maybe?

The smell gave me the inevitable erection. Having already been excited and thwarted that evening my balls were aching and swollen. I knew what I had to do if I was going to get any sleep at all but I had to remember the tissues. I leaned out of bed to pick them up and as I did I knocked my pillow onto the floor. In the dim summer moonlight that was spilling through my window I noticed something crumpled where my pillow had been. I picked it up.

I turned my bedside light on and then screwed my eyes shut until I could see properly. I was looking at Juli Patterson's knickers. I was holding them in my hand. Not only that, I knew there was only one way they could have got there. She must have taken them off when she lay recovering after I'd locked her in the laundry room. My heart started to beat faster and I felt the butterflies swirling in my stomach.

It could only mean one thing. I wasn't imaging the chemistry between us; Juli was egging me on. She was tempting me.

I grabbed the pillow back and my box of tissues. I was going to need them. Leaving the light on I took a closer look at her underwear. They looked like the kind she'd been wearing when she went up the ladder. Just a pair of plain white mini briefs, but to me they were treasure. A priceless sexual bounty full of forbidden scents and fantasies.

I examined the inside of the gusset. It was a soft fluffy cotton and there were vague marks where her sex had been in contact with the material. Not knowing whether I really dared or not I lifted that smooth cotton to my face and inhaled like a man coming up for air. The smell was strong, slightly sweaty and sea salty. To possess them was divine joy.

The urge to slip them on was overwhelming. I didn't resist it for a second. With the most delicious thrill of mischief and guilt I pulled them on and let the material rest against my pulsing prick. I knew my balls were now lying where the lips of her vagina had been when she was wearing them. The mental strength of the images in my mind was such that I didn't have to stimulate myself at all. The touch of the smooth cotton was enough. I only just made it with the tissues and there was a lot to catch.

It was strange, though. As soon as I'd come, the mischief and trepidation stopped being a thrill and instead I felt dirty. What the hell was I doing putting on women's underwear? Did it mean I was a pervert or something? Not knowing the answer made me feel worse. It was clear I didn't know myself very well and the part I knew I did not understand.

As quick as I could I took her pants off and hid them between the mattress and the bed base. I was exhausted and slept almost immediately but by morning, in spite of my guilt, the panties were calling to me once again.