A/N: The plot is mine, but everything else belings to J.K. Rowling's magical Harry Potter universe.

'No,' said Draco.

'What about this, then?'

'Hell, no.'

I didn't look up from my quill-chewing. 'That's a swear.'

'The hell it is.'

I looked up at Draco and grinned. 'It's a profanity. Do it.'

He grumbled, but pulled his wand out and flicked it desultorily at the jar sitting on our common room coffee table. I heard the satisfying 'clink' of two galleons settling on top of many, many more galleons (his contributions) and a not unimpressive pile of knuts, sickles and one button (I was temporarily short of funds).

It occurred to me that Draco and I curse rather a lot more than should be acceptable for a Head Boy and Head Girl. When we became lovers, the air of the Heads' dorm frequently turned blue with the number of omigods, Merlins, and fucks that sprang from our mouths when we were in the least bit in control of our mental faculties.

So I started a swear jar. With Draco's co-operation, of course. After I successfully deep-throated him for the first time and he let loose such an intensely loud swearword as he came that I was deaf for several minutes afterwards.

It started out as an old jam jar. But after we'd engaged in many pleasurable events in quick succession, I 'appropriated' one of Professor Snape's gigantic apothecary jars from the Potions classroom.

He's still swearing eternal and everlasting damnation to the person who nicked it. His current suspects are (of course) Harry and Ron, with Seamus as back-up. Slytherins, of course, are above suspicion.

He'll get it back at the end of the year. Hermione Granger is not a common thief.

I dropped my quill on the kitchen table, and turned to glare at Draco. 'These are the only two options,' I insisted.

He crossed his arms and stuck up his nose. 'Neither alternative is acceptable.'

God, I hate doing patrol rosters (oops, that's a profanity). Trying to design rosters for the prefects is rather like herding cats that are mainlining on steroids and energy drinks. After a good two hours of wrestling with next month's roster (Draco's contribution was massaging my feet, then slowly drawing each toe into his mouth), I had one spot left to fill. Someone had to partner Ron. And it was either Draco or me.

He was being his usual obstinate self, so I offered to do it. I don't want the poor house-elves following those two around the castle, cleaning up their blood as they go.

Draco leaned over menacingly. 'You are not spending hours alone with your ex-boyfriend, the Randy Weasel, checking dark classrooms, nooks, crannies and other places where quick shags are achievable.'

Ah. he's jealous. No wonder I was struggling to understand his mood. A jealous Malfoy has never darkened Hogwarts' doors before.

Still, it wasn't helping. 'Draco, the last person I want to shag is Ron. I'm sure the both of us can exhibit enough maturity for two exes to properly execute their duties.'

He raised an eyebrow.

'Okay,' I amended. 'I'm sure I can exhibit enough maturity for the two of us to properly execute our duties.'

A muscle ticked in his clean-shaven jaw as he tried to stare me down.

'All right!' he sighed, and threw up his hands. 'I'll patrol with the ginger git.'

I peered at him suspiciously. 'You won't kill him and hide his body under the flagstones?'

He rolled his eyes. 'No.'

'You won't hex him into another dimension?'

'I don't know how to do that, Granger.'

'You won't beat him up?'

Malfoy bared his teeth. 'Only if he deserves it.'

Good enough for me.

I completed the final entry, leaned over and kissed him. 'Thank you, Draco,' I whispered on a smile. 'I love you.'

He smirked. 'I love you too, you tormenting, manipulative snake.'

'Hey! I am not a snake!'

He deepened the kiss and drew me out my chair. 'I love snakes,' he murmured.

Then we went upstairs to conduct some more swearing.

'What are your plans for the swear jar?' Draco asked idly, twirling some of my hair around his finger.

We were in his bedroom, cooling down after fucking each other for an hour or three (it's not a swear when I'm narrating. Okay?) We lay on top of his duvet, letting the air brush over us. Even so, I'm at my happiest when some part of me is touching the glorious, irritating, sensual, foul-tempered, sexy git known as Draco, so I'd hooked a leg over his thigh and rested my head on his shoulder.

'Well,' I mused, 'it's not like we need the money for anything. You're loaded.'

'That I am,' he said smugly, trapping my leg between his and patting my arse.

'Then it should go to a worthy cause,' I said, ignoring him as he pretended to stick a finger down his throat. I sat up. 'I know one!'

'Oh, no.' Draco's eyes widened. 'Don't you dare say it – '

'Yup!' I said happily. 'The Society for the Promotion of – '

'You have got to be fucking kidding me!'

'Swearword,' I said smugly.

'Argh! You'll be the death of me, woman!'

Still, he leaned over to his bedside table, grabbed his wand and donated another galleon to the jar.

'Oh, quit bellyaching,' I admonished, straddling his hips so I had his full attention.

'Love,' he sighed with extreme patience, 'we can't give the money directly to the house-elves. I'm sure I've told you this more than once.'

'Yes, yes,' I muttered. 'I need to think.' Thoughtfully, I undulated my hips over his recently-acquired erection, while I leaned forward over him, biting my lip in concentration.

Draco placed his hands on my hips and ground slowly against me, taking one of my nipples into his mouth, sucking and licking.

I could feel myself growing wetter and wetter, slicking his erection. His eyes darkened as my breath hitched.

Sometimes I get chills when he looks at me like this – silently, with arousal plain in his eyes. He's not one for giving in to his emotions much. So when he lets his guard down, showing how he trusts me – this is why I love him.

Like this.

We'd been kind of energetic before, so we went a bit slower. When I looked down briefly to position myself over his cock, he sat up (not using his arms, o glorious inner core strength!) and gently held my chin. He likes to see my face when he enters me. And gods, do I like looking at his.

When he slowly slides in so that my entire sex is filled with him, it takes my breath away. Every time. Big. Hard. Hot. Yum.

This quickly became one of our favourite positions. I love it because I can control the pace. Draco loves it because he can lie back and let me do all the work for a change (his words, not mine); he's mesmerised by my breasts - compelled to massage them, pinch my nipples and bite when I'm long past the need for soft touches; and with just one touch of his finger on my clit, he makes me shatter.

Just thinking of him makes me…

Oh, Merlin…

I sped up, fucking his cock fast. I was on the brink of coming. Draco saw the emotions play across my face. We were millimetres apart. We could feel each other's laboured breath. Look into each other's eyes. He kissed me deeply, then in a low voice, told me how I looked when I came. How incredible I felt on his cock. How tight my pussy was. How I was the most beautiful woman in the world to him.

'Oh gods, please please please…' I begged him. My orgasm was just within reach.

He rubbed a finger over my pussy, coating it in my juices. It wasn't enough. I begged him for more.

He slid his finger into my arse.

My orgasm hit me like a freight train. The feeling of his cock and finger in me made me break apart. I convulsed over his now-spurting cock and howled at the ceiling.

Later…

'I have it!' I cried.

Draco didn't move from the spread-eagle position he adopted on the bed after he came. 'Do I have to do anything?'

'You'll love it,' I assured him. 'It's a prank.'

He twitched an eyelid. 'A prank, you say?'

'Yep. On the whole school.'

He smiled slowly, and kissed my nose. 'Granger, I think I'm beginning to rub on off on you.'

I grinned, and hopped off the bed, heading to the shower. 'I hope you'll peer-review my draft plans and improve their quality.'

He laughed tiredly. 'Bet on it, babe.'

'Also, you owe the jar five galleons.'

'Fucking hell!'

'Six!'

Of course, I increased the jar's coffers with my own contributions by….

… sixteen. Ahem.

Monday morning rolled around, and the students and staff of Hogwarts gathered in the Great Hall for that most important meal of the day – breakfast.

Except for Draco and I. We thought we'd sleep in and partake of the pantry items in our kitchenette before a double period of Potions, worse luck.

Later, Ginny told me how it went down…

'What is that raucous din?' snapped Professor McGonagall as she sat down at the Professors' table.

Professor Snape was clutching his head in his hands. 'That, Minerva, is the cacophony of the entire school body banging their cutlery on the tables, hollering for their food.' Suddenly, he banged his fists on the table, reared up from his chair and bellowed 'KEEP IT DOWN, THE BLOODY LOT OF YOU!'

The good Professor McGonagall was perplexed. 'Really, Albus, what's gotten into them?'

Professor Dumbledore shrugged, with a touch of amiability, to Minerva's suspicion. 'Nothing at all, it would seem,' he commented. 'No food has appeared on the tables, much against our best efforts to conjure it up.' He rose gracefully from his chair. 'I'm afraid, dear Minerva, we may be the victims of a prank.' He headed sedately off to his office, where he kept an emergency supply of sherbet lemons.

Professor McGonagall scanned the riotous Great Hall with her cat-like eyes. At the Gryffindor table, most of the boys were loudly complaining of their stomach cramps and how they couldn't go on for much longer, while the girls calmly drank coffee or tea while gossiping or preparing for their lessons. Mr Weasley, in particular, looked about set to take a very large nibble from one of the candelabra. Mr Finnegan had already started on the other side. Mr Potter was prostrate amongst the cutlery, asleep.

That took care of her usual troublemakers. But where was…?

Professor Snape was also conducting a stocktake of the Slytherin hanky-pankers. Nott: present. Zabini: present. Those great big twits Crabbe and Goyle: unfortunately present. But where was…?

McGonagall and Snape met each other's stares. Then narrowed their eyes.

'So you see, Professor, as a result of our diligence and hard work, we came up with a way to reward the industrious house-elves of Hogwarts School of Witchcraft and Wizardry without offending them!' I beamed with pride and self-importance as Draco and I stood before Professor McGonagall's imposing desk.

Snape and Draco, the traitor, rolled their eyes.

'With the money we made, we were able to purchase – for the entire cohort of house-elves – a really spiffing, shiny uniform! They can't get offended, since a uniform goes with work, and at the same time, we can subtly show our gracious appreciation for all their hard work.' I sat back in my chair smugly.

'Yes, well, Miss Granger, Mr Malfoy, that's a very noble cause, and I'm sure the house-elves will be very proud of their new acquisitions,' Professor McGonagall said slowly. 'Especially if it increases their dry-cleaning workload.'

'But what I don't understand, Miss Granger,' Professor Snape said, pinching the bridge of his nose between his fingers, 'is why every single house-elf is absent from their duties.'

I glanced at Draco. 'Well,' I said, 'we had some money left over. And since we couldn't give it to them, we decided to get them something they'd enjoy.'

Professor Snape loomed over us like an extremely large buzzard. 'And what, pray tell, was that?' he cooed.

Draco answered. 'Enough Firewhiskey to fill a swimming pool, sir.'

Snape glowered. 'So you're telling me the entire house-elf population is – '

'Completely and utterly shit-faced, sir. But they're very happy.'

So, we had detention every day for a month. We ended up scrubbing parts of the castle I never knew existed. But it didn't matter. Those who prank together, scrub together.

And those who laugh together, stay together.

The End.