And yet, gradually, imperceptibly, the relationship between us had developed and altered; nothing major, nothing tangible even, just a sense that roles were being assumed, territory was being marked out. I was in no way overtly domineering, and yet it seemed clear - to me anyway, and I think to Paul as well - that mine was the dominant character. And while there was absolutely nothing sexual in any of this, there seemed to me to be emerging a latent erotic tension between us. I couldn't put my finger on it, but it was there, lurking in the fringes of our ordinary domestic routine. But hey, I thought, there's no point trying to second guess these crazy Americans: Fetishdoll was about as normal as a teapot with no spout, so I knew better than try to figure out her brother. Just wait, I thought, something will turn up. It always does with this family.

Work, meanwhile, was progressing with the same manic uncertainty, and it seemed only a matter of time before my acid tongue got me the sack. There was something about the place, about the work, which seemed to bring out the worst in me. Honestly, I'm normally a fairly placid sort of person, someone who goes about her business quietly, not making a fuss, not causing a scene, just calmly getting on with things. But since I'd started in this job I had turned into a harridan, a crazed-eyed Medusa of the first order, snarling insults at clients and hurling instructions at staff with all the decorum of Saddam Hussein with a toothache. I couldn't help it; I just seemed to lose my temper so easily.

Which brings me to that day.

It had been a long, hard day, with a series of arguments and showdowns culminating in me issuing a "back me or sack me" challenge to my boss. Alarmingly, he said he would go away and think about it, not the response I had anticipated, and I was feeling a little edgy as I gathered my things up to go home. So when the phone rang at five to five and I heard the nasal tones of Bob from IT my heart sank into my toes and my will to live started to scratch about in search of any available escape route.

"Yes Bob?" I replied wearily. Gradually, as Bob droned on with his message, my jaw began to drop wider and wider, incredulity sweeping over me, a flush of heated indignation leaving its reddened mark on my neck and face. I couldn't believe what I was hearing. I had a large document, a couple of hundred pages or so, which I had written and which, by law, had to be made publicly available. I had put in a requisition to the IT team to convert it to pdf so that we could post it on the website. Bob was telling me how much IT proposed to charge for this routine task, and I didn't like what I was hearing.

"Fuck's sake, man, you're living in a parallel universe," I exploded. "You can't be fucking serious, you're completely stark staring mad, you bog-eyed little shite bag; what are you, some kind of half wit?" There was a silence from Bob's end of the phone. I began to draw daggers on my deskpad, imaging scenes of torture which I could inflict on the vile little man. Bob tied up and flayed with a whip, bound and gagged and subjected to acts of pain and humiliation. Oh, yes, oh so tempting...

"Are you seriously suggesting," I continued, "that it will cost me £2000 to convert one lousy Word file into pdf? Suffering God, I could get a medieval scribe to write the whole bloody thing in burnished gold on the finest vellum for that price." I could hear a sharp intake of breath from Bob. "Probably do it quicker than you lot, too," I concluded and slammed the phone down before my blood pressure soared into orbit and dragged me kicking and screaming into the territory of a full blown heart attack.

Right, I thought, as I slammed the front door and marched down the hallway into the living room an hour later, after a run-in with a would-be groper on the train who was now nursing a broken finger or two, right, I thought, I'm going to have a long, cool spliff, a glass of wine, put my feet up and chill out. And woe betide anyone who gets in my way.

"Hi," came the voice of Paul through the kitchen door. "I'm just cleaning the cooker." The man was obsessed with cleaning things. It was extraordinary. I ignored him and started to rifle through my CDs, looking for Beethoven's Sonata for Cello, which I knew would cheer me up. The allegro vivace, fast and lively, spinning and flitting, would match the state of my mind. Except it wasn't there. Nor were dozens of others, and instead of the teeming, cluttered mass which normally adorned the shelves, and which I knew and loved, were serried ranks, in strict alphabetical order, of CDs and cassettes.

"Ah," said Paul, entering from the kitchen and witnessing my consternation, "I tidied them up a bit. Not all of them fitted the shelves, so some of them are in the cupboard over there." I bit my tongue. We had gone through this before, and I had declared my music collection off limits to Paul and his fanatical duster. He sensed my dissatisfaction and handed me a juicy joint in an attempt to deflect my attention. It didn't work.

"What have I told you?" I exclaimed, taking the joint and lighting up. "What have I told you?" Paul looked downcast and slightly alarmed. "You deserve a bloody good hiding," I concluded, dragging deeply on the joint, delighting in the toasted, slightly sweet taste cascading down my throat. I said it without thinking, and it was as big a surprise to me as it was to Paul to hear the suggestion. There was silence for a second.

Actually, now that the thought had entered my head it was quite appealing. Mr Perfect had been bugging me for a few days, and now he had made a big mistake, so surely, I reasoned, he deserved punishment for it? I had never got off on a dominant thing before, but now, in these circumstances, it seemed right. And it excited me. I was aware of an electric buzz low in my stomach, the first frisson of sexual tension. I looked at Paul threateningly, and lowered my joint into the ashtray.

"Don't you?" I exclaimed. "A damned good spanking is what you deserve for that. You knew those CDs were off limits didn't you?"

"Yes," he replied.

"So you deserve it, then?"

"Yes,"

Well, that was a facer. I digested what he had just said. He had agreed that he should be punished. A grown man had told me he thought I should spank him. This was new territory for me. I'd been on the receiving end of such things before, but had never been in a position to administer them. So here I was, Harriet the nervous domme.

Paul meanwhile, looked serenely calm as he faced the proposition. He really was going to go through with this, it was clear to me.

"Very well," I said huskily, "I'm glad you see the error of your ways and acknowledge the repercussions." Now what did I do, I thought, frantically. God, Harriet, you get yourself in some pickles.

"Yes," he said. "I'm very sorry."

"Sorry isn't good enough, I'm afraid. Let's get those trousers down." My breath caught in my throat and I watched, unmovingly, as Paul began to unbuckle his belt and ease down the zip of his jeans. Bending, he eased first the left, then the right leg off and stood before me in his knickers. "Them too," I added, with a peremptory nod in their direction.

Paul stood for a fraction of a second before his hands moved automatically to the waist band of his knickers and he slid them down. I moved to the settee and sat facing him.

"Over here,"

Paul walked towards me, his prick swaying gently. It was rather a nice one, I have to say, fairly long even in its flaccid state and satisfyingly thick. I indicated to my lap with a flick of the eyes and slowly, almost languidly, Paul stretched himself over me, his cock nestling easily into the vee of my thighs. My God, I thought, there's a man across my lap with his bare arse waiting to be spanked. I could feel that my pussy was damp, and a wave of sexual excitement, that wonderful, tense anticipatory sort which only comes when you try something for the first time, settled itself into every inch of my body, insinuated itself into every crevice of my mind.

Crack! I let go with the first spank. It wasn't very good, badly timed and skidding ineffectively off his right cheek. It probably hurt me more than him. Embarrassed, and trying to reassert my dominance, I followed up immediately with another, much better judged slap, catching him with a satisfying snap and raising almost instantly a reddened flush to his buttock. Hmm, this was okay.

I let go another volley of slaps, alternating cheeks and trying to vary my landing point. Paul had said nothing up till now, and I suspected I wasn't doing it hard enough. I experimented with a much harder blow and felt Paul's body tense with shock as it hit him. He stifled a sigh. More promising, I thought.

"I hope," I said, in between spanks of varying force, "that this teaches you a lesson. You will not mess with Harriet's things. You will not take her for granted. You will do as she tells you." I had settled into a rhythm now, and had inflicted about fifteen or so blows, mostly not very hard. His bottom, nicely presented to me as he lay across my lap, was very cute, tight and firm, deliciously small and very inviting. It was becoming distinctly red now, with one patch in particular, on his right buttock, turning quite a livid purple. Crack! Crack! I unleashed a couple of extremely hard spanks, one on top of the other, eliciting a clearly audible groan from Paul. And then I felt it.

He was hard.

Of course, there was no reason why he wouldn't be. Wasn't I damp to the point of incontinence? But it was still a shock, a very visual, and tactile, show of sexual excitement from Paul, the first I had encountered since we met. This evening was spinning off into uncharted territory, we had flown off onto a different plane. And I was experiencing, for the first time, the sexual excitement of power and dominance. I used power and aggression every day at work, in a purely platonic sense, a very unfulfilling and unsatisfactory sense, but this was the first time I had ever harnessed the dominant part of my personality for sexual reasons. And, I couldn't deny it, I loved it.

As this man lay before me, naked below the waist, his red arse exposed helplessly to me, completely in my thrall, tensing and arching beneath the onslaught of my hand, I felt such a surge of excitement, a rush of sexual arousal different from any I had ever known. I felt power, yes, but much more than that. Simple power over someone is easy; any playground bully can do that, and it is neither impressive nor important, relying on nothing but force and stupidity. But to gain the complicity of the dominated person, to win sufficient respect from him to allow himself to be subjugated to your will, that is a very different thing, a most potent force, and I was humbled that Paul thought enough of me to give himself over to me in this way. I had power, but with it came responsibility. I had earned this position; now I had to keep it. But that was for later: for now there was too much fun to be had.

Crack! Crack! Crack! I unleashed another thundering salvo of blows on his pained posterior. He winced and moaned with each blow, but I could feel, stiff and hard against the fabric of my skirt, that he was still excited by the ordeal.

"I think you may have learned your lesson," I said, delivering a couple more slaps to enforce this opinion.

"Yes I have," he groaned. His voice was hoarse and I could hear his pain.

"Just five more," I replied brightly. I heard him groan, but he did not complain. Accordingly, I set to, and inflicted five more almighty blows on his already tortured backside. "I hope this will be a lesson to you, but I'll be surprised if you don't end up spreadeagled across me again before long. What do you say?"

Paul couldn't work out whether to respond in the affirmative or the negative to this, so I punished him for the delay with another quick slap, so hard the noise reverberated round the walls of the living room and seemed to echo back at me from all corners.

"Now then," I concluded, "what are you going to do about that damned great stiff thing that has been poking into my thigh for the last twenty minutes?"