Elizabeth didn't behave very well at dinner parties, or at least that was what her husband Sebastian told her. He was adamant that this one had to be different.

"For God's sake, Liz. Don't do your usual. Don't get drunk and upset half the guests with your tasteless jokes. You know I'm in line for a promotion and my boss listens to everything his wife says. This is make or break."

Elizabeth was fastening her earrings at the time, half smiling to herself as she pictured the boss' wife. 'A real dog', Sebastian had described her once, and she was, she really was.

"I'm counting on you," Sebastian reiterated. "If you mess up, my wrath will know no bounds."

"I shall be the very model of propriety and wifely modesty," Elizabeth assured him.

Which she was, up until the dessert course, when the male guest next to her had refilled her wine glass for the third time and the boss' wife was telling her for the second time how a wife's support was absolutely crucial for a husband's advancement.

"And how do you support yours?" she heard herself asking, loudly, as if from a long way away. "Do you bring him his slippers?"

The rest was a bit of a blur. She remembered men laughing and women gasping, and Sebastian's eyes glaring at her - two smouldering embers on the other side of the table.

It began to dawn on her what she'd done in the car on the way home.

"Sorry about that!" she tittered, rubbing her cheek affectionately against Sebastian's arm.

The arm stiffened.

"'Sorry' doesn't begin to cover it. You'll find that out when we get home."

Elizabeth gulped. She knew what her husband meant and it was no joke. He hadn't spanked her many times in their married life, but when he did - boy, oh boy.

The rest of the journey passed in silence. Sebastian's spankings were painful in the extreme, but this didn't stop his unique invasive thoroughness from being the biggest turn-on she'd ever known. Her feelings swung between the two opposite poles of dread and excitement.

No-one could be as coldly precise as her husband when he put his mind to it. He drove the car into the garage, applied the handbrake, turned off the engine, got out, closed the garage door, opened her door and allowed her to proceed ahead of him into the kitchen, moving all the while like a robot. He might have been ordering wine in a restaurant when he said calmly:

"Go upstairs, get into your pyjamas, then come down here."

Elizabeth felt like a small child being sent to bed, except that she wasn't being sent to bed. She wished she was. She did as she was told, putting away her jewellery and hanging up her dress with trembling hands. Then she pulled on her flannelette pyjamas, slowly, appreciating the softness of the fabric as it passed over flesh that had not yet been punished. She put on her slippers - God! Why had she ever thought of that joke about slippers! - and walked downstairs, hugging the banister rail as if it was a friend she wouldn't see again.

Sebastian was waiting for her in the living room. He'd removed his dinner jacket and rolled up the right sleeve of his shirt, and he was sitting in the middle of the sofa. Elizabeth knew what he expected her to do. She had to walk over to him and place herself over his lap so that her bottom was presented at exactly the right angle to be the target for his descending hand.

For some reason she felt unable to do it. She stood in the doorway and there was silence for a few moments until Sebastian took command.

"Come here. Stand there. Bend forward ... lie here ... just here ... and take your feet off the ground."

She was in the familiar position. She wasn't comfortable - how could she be comfortable in the circumstances? - but she was supported by Sebastian's thighs in the middle, in a way that made her bottom the highest part of her, and by the sofa at each end. He shifted a little so that she nestled further into her posture of submission. Her torso made complete contact with him as if she'd been a rag doll thrown across his lap. She was both ashamed and thrilled.

He cleared his throat. He was the stern administrator of her punishment.

His fingers slipped expertly under the waistband of her pyjama bottoms and then, two-handed, he slid them up, over and down the curve of her poised buttocks. She felt a frisson of pleasure as the material pulled away from her pubis, and a flood of arousal fluid coincided with the final tug to release the garment from under her. Her body's betrayal was humiliating but Sebastian acted as if he hadn't noticed.

The first rapid slaps, which were divided roughly equally between her buttocks, were almost pleasurable. Involuntarily she thrust her bottom up to meet them. But they continued without abate, sometimes on one buttock only, sometimes on both, sometimes on the round swell of her plumpness and sometimes across her sit spot. They went on and on, leaving nowhere unchastised, rapid and steady. It was their sheer accumulation which wakened the fire in her flesh and made it grow and grow until she couldn't bear it.

She lashed out to try and soothe it but her hand was seized, twisted and tucked under the arm which lay firmly across her waist to hold her down.

The spanking continued. Elizabeth's flesh burned more and more. She began to kick with her legs to provide a distraction to the pain, but Sebastian had an answer to that, too. He swung one thigh wide, half pushed and half dropped her legs down between his own, and gripped her with his knee. Now she couldn't move her lower half at all, but her bottom was still perfectly presented for its punishment.

Sebastian had video recorded one of her spankings once and then sat with her afterwards to watch it. She had been able to see how with each slap he cultivated the rosiness of her buttocks. He was a painter, colouring her bottom red one brushstroke at a time. She'd been horrified to see her own expression - the grimace of pain . She supposed she had it now.

"Please, Seb."

"You've had a fraction of what you deserve."

"But ..."

"I warned you."

There was no stopping him. He was like a machine, delivering pain with every impact, drilling the force of his will into her humbled flesh.

Eventually he landed one harder slap across both her buttocks and stopped. She lay there, feeling the smarting sensation blossom like a flower. She wanted to cry but was only able to moan, softly. His breathing betrayed the effort he had put into the spanking.

"I can only hope my presentation will appease the boss."

"Wha-what presentation?"

"I promised I would punish you severely and he wanted evidence."

"So you ..."

"Yes, all this is being filmed."

"And you're going to show him?!"

"Him and his wife."

"But you can't! It's compromising! It's private between us! I won't be able to show my face at any of their do's ever, ever again!"

"That's perhaps just as well. By your behaviour, you forfeited all say in the matter but I'll tell you this much: if I'm to keep my job, I have to do something a bit exceptional. In any case, the DVD will be there for you to watch whenever you need a reminder. Next time you're tempted to disobey me, perhaps it'll help you remember the consequences."