I glanced up at Mark as he finished wiring two leads to a small box of electronics. The other ends of the leads were connected to a cold, metal dildo, which was strapped firmly inside me. This was my punishment for last night.

I shuffled slightly on the bed, the bonds allowing me very little movement, but the device stayed firmly inside me. My ankles were tied to the front corners of the bed, and my wrists were tied to a table that was fixed in place over the top of the bed. My old word processor was on the table, complete with a built-in printer and phosphor green screen. It must have been a decade since I last tried to write a novel on it, and it was beginning to make the bedroom smell like the musky attic Mark had brought it down from. My hands had just enough freedom to use its grimy keyboard.

I shifted my weight slightly. I could just about stay comfortable if I squirmed about every now and then, but even with the heating on, I was still cold. This was partly due to the metal dildo, but mainly because Mark had told me to wear only stockings, suspenders and a hairband. My hair was notoriously frizzy, and I tended to complain about it getting in my mouth during our sessions.

"Let's see if this thing still works properly," said Mark. He pushed a button on the small box.

I let out a very sudden and loud noise, dampened by the pink, rubber gag held in my mouth by a tightly fastened head harness. It felt like the insides of my genitals were on fire for a split second. The shock was soon followed by a second and third, at seemingly random intervals.

"It seems to be working just fine," he said to himself, smiling. "This device will now give you a few seconds' worth of electric shocks every five minutes, on the dot. In light of your disobedience, I would normally have set it to shock you more often. I don't want it to put you off your writing, though. It's going to be your incentive, not something that distracts you."

This was the first time he'd used electric stimulation on me in months. He shared most Sunday afternoons with a soldering iron, making God knows what, so he must have been on cloud nine when he discovered a way to combine his two favourite hobbies. He quickly found out how much I hated it, though, and thankfully he respected my limits. This time he deemed it a suitably harsh punishment. I made a mental note to be extra careful to remain obedient to him in the future.

It wouldn't have surprised me if he got the idea for the typewriter from his new friends on a mailing list he joined a few months ago. It consisted of a few dozen dominants who shared tips, stories and techniques with each other. He must have told them a bit about me, and how I used to aspire to being a writer. While I'd always wanted a supportive boyfriend to encourage my creative side, this wasn't what I'd had in mind.

"One last thing," said Mark, reaching into our blanket box. My eyes widened as he pulled out a pair of nipple clamps connected to each other via a small chain. They were my second least favourite device, after the electronics.

I tried to plead with him. Something vaguely resembling the words "No, I'm sorry! You really don't have to use those! I won't do it again!" made it out of the gag. He probably couldn't tell what I'd said, but my tone of voice alone conveyed that I would have done almost anything to avoid him using the clamps on me.

"You should have thought of that yesterday," he said, carefully placing them on my areolae, one at a time. The pain soon died down, but as soon as I was beginning to block it out into background noise, the dildo gave me several more sparks, causing me to let out another muffled scream.

"Now for the first part of your punishment," said Mark.

A dulled noise served me as saying "First?"

"The first of two parts," he said. "You must write something for me. Something that will turn me on. If you write something that doesn't do it for me, it won't count, and you'll have to start again. Once you've finished, and I've approved of what you've written, the second part of your punishment will begin. After the second part, and only then, I will untie you. Do you understand?"

I nodded.

"Good," he said. He playfully tapped the chain hanging from my breasts, watching it swing back and forth, before walking away. "I'll come back later," he said. He left the room, closing the door behind him.

I shouted through the gag. There was no response. I shouted again, but I couldn't hear anything from outside the room. He'd left me. I protested one last time, a halfhearted attempt at a swearword, that he probably didn't even hear. The pain from the nipple clamps had become less intense, so I tried to think straight. He'd given me a task to perform for my punishment, and would only let me go once I'd completed it. I had to write something sexy for him.

I tried to think of an erotic story to write, but my mind went blank. I hadn't written any fiction in years, although I'd always meant to take it up again. I couldn't even think of a rudimentary plot. After a few minutes thinking, with a painful interlude of shocks, I finally gave up on the idea and started to write about the previous night, just so I was at least making some headway. So I at least FELT as if I was getting closer to the end of my punishment.

I nearly always came home from work an hour or so before you. While waiting for you last night, I started to skim through a bondage novel I'd bought several years ago. I guess I was just bored more than anything else, but the more I read, the more my boredom was replaced by desire. As I grew more and more aroused, I started to fantasise about you dominating me in various ways. I put the book back and started to grope myself, over my clothes at first, then sliding my hand down, inside my plain combat trousers. The next thing I knew, I was lying on top of our bed, fingering myself. That's when I heard you arrive.

I quickly put the rest of my clothes back on and scurried into the bathroom to wash my hands. I guess you must know me pretty well by now, as you seemed to already know the answer before you asked me what I'd been doing. We'd already established that I wouldn't ever keep any sexual thoughts from you, so I told you the truth: I had gotten horny and had started to masturbate. I knew you'd specifically forbidden me from pleasuring myself, but I just got carried away.

You just shrugged. "Well don't let me stop you," you replied.

"I'm sorry?" I asked.

"You heard me."

"Well, the moment's kind of passed now that you're home," I said, looking at the carpet.

"Masturbate, my little slut. That's an order."

I swallowed, the sound amplified in my head. It always amazes me that you can turn me on so quickly by such simple action, such as casually groping my breasts, or in this case, with just a single command. I obediently trotted back into our bedroom and undressed, fully this time. By the time I was sitting naked on our bed, you'd taken off your coat and bag and followed me into the room.

"You realise I'm going to have to punish you for disobeying me, don't you, slave?" you asked.

"Yes, master," I replied, gazing at the floor again. My fear of what the punishment would be was eased by the thrill of submitting to you again. Already my head was spinning with ideas, possibilities, hopes of what you might make me do. Remembering your order, I slid one hand down to my crotch and the other up to my breasts, lying back as I started to finger and grope myself. "Do you want me to masturbate until I orgasm?" I casually asked, as if we were deciding what to watch while having dinner. I immediately wished I'd kept my mouth shut.

"Yes," you replied. I looked up at you, searching your face for any sign that you were teasing, but you looked deadly serious.

"Are you going to tie or gag me?" I asked, hoping you wouldn't consider it an insolent request. We both knew how much that would help me to orgasm.

Your eyebrows scrunched together for a few seconds as you considered the options. It was as if you had become a cold machine, like those devices you tinkered with each weekend. "No," you eventually decided. "But I will permit you to use any gags, restraints and toys on yourself."

I cleared a stack of books from the wooden blanket box and lifted its heavy lid, the hinges creaking. The inside smelt of the varnished wood of the box itself, mixed with the scent of the various rubber items that constituted most of its contents. I rummaged around, examining the various restraints and gags, before settling on the denim straitjacket, the rubber hood with a large hole for the wearer's mouth, and the simple ball gag, sans head harness.

I'd owned the jacket since before we met, and when I was single I'd learnt how to buckle the sleeves together before putting my hands in them and zipping the front up, then fold my arms and slip the buckle behind my head. It wasn't as good as sliding the sleeves through the straps at the sides, as I knew I could escape from it at any time, but it was about as securely tied as I could get by myself. I figured that with the gag and hood as well, it would be enough for me to climax.

I took a deep breath and tried to slide the hood into place around my head. It took a few attempts to get it as far as being tightly wrapped around my forehead. After a while of pinching and dragging it, then trying to pull it away from the parts of my skin and hair that it was moving with itself, my face was completely enveloped. All I could see was darkness, except for the bright light of a few inches of our bed, almost luminous in one eye through the tiny holes for me to breathe through. I adjusted the front of the hood so that the holes were in front of my nostrils properly, although I could still see through them. The smell of rubber was intoxicating, augmented by my decreased senses of hearing and vision.

I picked up the ball gag and surprised myself at how easily I could put it on without looking. The entirety of the hood's hole was soon filled up by my open mouth, my lips wrapped snugly around the rubber gag. I moaned happily.

Next, I tried to pick up the straitjacket but I couldn't feel it lying on the bed anymore. I suddenly felt it on my back and realised that you were going to help tie me after all. You were holding the jacket up so that I could easily put my hands through its sleeves. You then zipped up the front, and I put my arms through the straps at the sides, almost purring with the thought that I wouldn't be able to escape until you took it off for me. I felt you tie the sleeves' buckle behind my back, before fastening the two other buckles that ran between my legs so that I couldn't simply lift the whole thing over my head. Then I couldn't feel your touch anymore, but my outfit was complete.