"Have you ever done that?" I asked.

"Good god, no," she said, rather too abruptly. I tried not to take offence; after all I had deliberately forced myself to act as "dirty" as I could, in response to her assertion that she couldn't understand how I could do such things.

"No?" I replied. "Never stuck your fingers up your arse, then?" I continued crudely.

"No! Not in... in... in the front, either."

I tried to understand this one. Was she telling me she had never played with herself?

"What d'you mean?" I asked. "Have you never had a wank?"

"No."

"Never?" I exclaimed incredulously.

"No."

"Good god, woman, whyever not?" She looked morosely at me, embarrassed by the conversation and shocked by my reaction to her announcement. "So," I continued, "you only ever come when your husband has his way with you?" Again, she remained silent, and I thought about it for a moment.

And then I realised: this woman has never had a climax in her life.

I was amazed, but as I thought about it I realised it must be true. I doubted that Mary and Allan had much of a sex life, and the woman was so anally retentive she was hardly likely to be a sexual predator in bed, so she almost certainly would be one of the "lie back and think of England" brigade. I shivered involuntarily at the thought.

"Well then," I remarked brightly, "we'll have to do something about that, won't me?" I swear if this woman gave me one more "shocked and horrified" look I would ram her head down the toilet and flush it. Everything which was happening was what she had fantasised about; moreover, it was the reason she had come. It wasn't my fault she hadn't believed it would really happen. Set a slave girl on a mission and you're apt to find that she carries it out: I have had too many reddened and bruised arses not to know that I have to perform. Mary, little naive soul that she is, hadn't appreciated this. And now, whether she liked it or not, her fantasies were coming to life under the ministrations of Harriet the Slave Girl.

"How do you want to do it?" I continued, not really expecting an answer. I wasn't disappointed. "Do you want to do it yourself? Or me do it for you? By hand? Mouth? What?" Total silence. It was harder than dealing with a homesick child on its first day in school.

I got to my feet and took her by the hand. Reluctantly she stood up. This was a peculiar situation, to be sure: I was being a dominant submissive, something of an unusual combination. People often display both sides, but not commonly at the same time. I knew, though, that if I was to satisfy the woman, as my Master would later expect, that I would have to take the lead. I reflected that she was so shy, nervous and uncomfortable I would have to make things as easy for her as possible. That ruled out Mary performing on herself: she could never do that in front of me. I suspected, too, that she would be unwilling to have any eye contact during the process, as that would embarrass her even more. The answer presented itself to me.

"Take your tights off," I said. "And don't bother arguing, it's a waste of time." Terror stricken, she did as I told her, struggling to pull the tights down down without disturbing her skirt or revealing anything of herself to me. I helped by ostentatiously looking away. "And now the knickers," I added. Mary would wear knickers, I thought, not panties. She did, too, enormous, billowing things the size of a small parachute. "Jesus, Mary, you could hide a football team in these. They must go up to your neck."

The poor woman's face did its impersonation of an aubergine again and I took pity on her.

"Okay, sit down again. Not right back, though, up to the edge of the seat." She did as I requested and sat with her hands clenched on the arms of the chair, as though she was watching a horror movie. "Now you may not believe this right now, but you're really going to enjoy this. Trust me, I'm a slave girl."

I lowered myself to my knees in front of her and looked up, smiling mischievously. She returned my look with a nervous grimace. I took hold of her long skirt and wafted it gently in the air, revealing her chubby knees. She was in her mid-fifties, and not in wonderful shape, a bit on the plump and round side, having let herself go somewhat at the onset of the menopause. Something of a change, I reflected, from the delicious, virginal little Jenny whose pleasure I had attended to the previous night. Not exactly beauty and the beast, but certainly from the sublime to the ridiculous, if a cliché has to be used.

I lifted the skirt again, higher this time, revealing her cellulite-dimpled thighs. They could only be described as sturdy. I lowered my head and descended beneath the skirt, my eyes in line with her pussy, and I looked up. She was very hairy, with large, pouting lips which were already puffy, but still dry. I kissed her leg and began to work my tongue upwards. Letting the skirt fall, I allowed myself to be covered by it, concealed, hidden from Mary's view. I licked and lapped upwards, getting closer and closer to her pussy. It was very hot, with both the confinement and the heat from Mary's excited body, and I felt myself begin to sweat. I tracked my tongue upwards and felt the fuzzy beginnings of her straggly bush. Blowing gently, I caressed her quim with my breath, preparing it for the forthcoming action, and I felt her legs shiver. God, she was sensitive: I hadn't even touched her yet.

I adjusted my position, making myself more comfortable, and laid siege with my tongue to her untutored and unsuspecting pussy. I lapped at it slowly, feeling for the first time her engorged lips. Stroking up and down, I rolled my tongue around first one, then the other, and then began to ease it between them, pressing inwards, into her vagina. She was still fairly dry, but becoming moist, and I produced extra saliva to help the process. After a couple of minutes, she was fairly well lubricated and my task became much easier. I began to roll and play my tongue inside her, pressing and probing, tickling around her urethra and licking downwards before tracking up again, up and up, towards her clitoris, that poor, neglected, underused little ball of nerve endings.

Hers, actually, was rather large, one of the biggest I have ever seen, or touched, rather, since I could see nothing. It was quite delightful, in fact, a joy to play with. I sucked on it energetically, falling on it with relish, quite forgetting that its owner was very unused to having it dealt with in this way. She shrieked in alarm and I apologised into her minge, returning to my task with a greater sense of decorum. I licked and sucked gently. Mary began to moan, getting louder and louder, and I was concerned at one point that she might be ill. I felt her hands through the fabric of her skirt, clutching my skull; I don't think she could decide whether she wanted to pull me away or push me closer, and instead she just laid her hands on me. Her legs tensed and she pushed them further apart, allowing me to press my face harder into her.

She was moaning with every short, rapid breath, and both the volume and the pitch were rising incessantly. If she didn't come soon, I thought, she was going to break every pane of glass in the house. I sucked harder, grazing my teeth slowly and gingerly down across the generous circumference of her clitoris and her squealing reached fever pitch. She let out a yell, a single, sustained note - high C, I think - and her body shook, jerking and quaking like an epileptic. The shriek went on, her body quivering beneath me, for a good minute, and by now I was gratified to feel a huge, slimy slick emanating from her enraptured pussy. Finally, she ran out of breath and the moment subsided, and she flopped back into the chair silently. I emerged from my tomb, my mouth and face covered in her juices.

"All right then, Mary?" I asked insouciantly.