"Alright, 'en," Rose grinned, shutting her bedroom door behind her and pressing her bare back and bottom against it with a pleased expression on her face. "Ten quid. Cough it up," she tilted her head back, speaking to the TARDIS around her, smug as could be - even with her barely towel-dried hair sticking to her neck and naked shoulders.

The TARDIS gave a groan of annoyance before a pleasant gear-clicking noise came from the bedside table beside Rose's bed. Rose Tyler marched, naked, to her bed and opened up her drawer, happy to find a ten-pound note, un-creased and unmarred, sitting in it. She pulled it out and fanned the air around her burning cheeks with it.

You see, when you travel in space for long enough, you begin to find ways to amuse yourself aboard whatever your chosen vessel may be. When that vessel was a slightly cheeky, conscious being with a leaning toward femininity and immaturity, those ways of avoiding boredom tend to be slightly mischievous.

For Rose Tyler and the Doctor's TARDIS, their chosen sport was a half-dare, half-bet that the two had going between them. The TARDIS would wager money that Rose couldn't make the distance between the bathroom - post-shower, in the buff, still dripping wet - and her bedroom, without being caught by the Doctor, and Rose would take the challenge.

She had yet to be caught, and so, Rose was winning.

The relationship between TARDIS and human was made possible by the tiny - miniscule, really - part of time-vortex still hidden in the recesses of Rose's mind, after she'd absorbed the energy of said time vortex into her mind to save the aforementioned Time Lord from inevitable death by Dalek. Rose thought of the ship as a sister, and the TARDIS probably saw Rose as a plaything; it was marvelous, in Rose's opinion.

Each time, the challenge got harder. At first, the TARDIS had literally put the bathroom across the hall from Rose's bedroom, to make the challenge easy - and at that point, Rose had still been allowed to cross the hall with a hand-towel to cover herself as best she could. After that, the TARDIS had placed the bedroom closer to the console room, hiking up the risk of Rose running into the Doctor, and then pushed the bathroom further into itself.

The Doctor was ever curious as to how Rose continued to have money on her person, wherever on Rose-period Earth they went, but she waved him off with an easy answer like 'Mickey got it for me', or 'I lent it off my Mum'. Rose had made a point of dropping silly phrases to annoy the TARDIS, whenever their resident Time Lord asked about the money - phrases like, 'oh, I'd be naked without a bit of dosh on me', and 'oh, well, a girl has her ways of making cash', in a teasing tone that made the TARDIS do something akin to eye-rolling; a swift groan of machinery within the main console.

Today's challenge had been especially hard. The TARDIS had bet Rose ten quid that she'd be caught today, because she'd hiked up the risk to extraordinary measures; she'd put Rose's bedroom accessible from the console room - the door right in view to anyone walking into the TARDIS - and put the bathroom right next to the Doctor's bedroom, which was next to the library as he liked to read while Rose slept, his nightly routine only rarely including sleep.

Either way, the chances of running into the Doctor had been the highest yet today, so the usual bet of five pounds had been doubled. Rose had passed the challenge with flying colors, if the Tyler girl said so herself. With a chuffed giggle, Rose got dressed and tucked her money into the back pocket of her jeans, before leaving her room, hair still wet but tied into a low ponytail, and charging into the main control room, ready for an adventure.

Rose and the Doctor disappeared for a whole day - something to do with Elf-like creatures, the TARDIS noted, tapping into the thoughts of the two - and that gave the TARDIS time to plot.

The challenges were too easy - Rose was beginning to get cocky, which meant she wasn't going to play it careful the next time. The ship had let Rose Tyler win on purpose, the last ten times. She had had to increase the ante today, just to get Rose to play with her - because Rose was getting bored of their game.

Now was the time to strike - while the human child was overconfident.

The Doctor and his Rose returned from their adventure on the fourth bog planet of a galaxy called Loxar fifty-two, both soaked to the hip in mud, with spotty smatterings up their torsos and across their faces, clumping hair into bunches and fueling a hilarious discussion about a planet where cleanliness was considered rude.

"I think I'll jump in the shower," Rose decided aloud, still laughing, and dusting her muddy hands over her muddier jeans in an attempt to flick away some drying dirt.

The Doctor nodded his agreement and pulled off his filthy coat, grinning and shaking out his hair, sending mud droplets flying all over the room. Rose laughed out, holding out a hand to keep from being spattered by his rudimentary self-cleaning technique. The Doctor straightened, taking off his jacket. "I think I'll join you," he said brightly, before he'd thought about his choice of words.

Rose's laughter caught in her throat and she choked in surprise, eyes bulging at him. "Uhm, ah … Pardon?" she asked incredulously, cheeks turning bright pink. The corners of her mouth yanked downward at the boldness of the statement, but her stomach fluttered slightly at the implication of what he'd just said.

The Doctor blinked at Rose for a moment, before exclaiming, "Oh!" in mortified embarrassment. "Sorry, no, that's not what I meant to say!" he apologized, chuckling nervously. "I meant to say … that I should do the same," he clarified, his own cheeks turning a rather lovely shade of red. He grinned awkwardly at Rose, biting back the urge to smack himself.

Rose gave a nervous laugh of her own, swallowed and nodded. "Yeah … right, yeah," she replied, averting her gaze from the Doctor. "Yeah," she repeated, before backing toward the halls of the TARDIS. "I'm gonna have a wash, then," she reiterated, before turning away quickly and raising a hand to the side of her face to hide her burning cheeks.

The Doctor cringed outwardly, the moment Rose disappeared into the halls of the TARDIS. "Nice one, Time Lord," he muttered irritably to himself, eyes widening in disbelief at his own mistake. "Why don't you just invite yourself into her bed while you're at it?" he clawed the air at his sides in utter shame, before marching into the ship toward his own washroom. "Dirty old man," he added, just for good measure.

It was at this point that the TARDIS contacted Rose with a new dare. Rose was just stepping under the hot jets of water in the bathroom as a voice echoed inside her head. 'Twenty pounds says you won't make it from here to the bedroom, doing a loop past the console room and past the Doctor's quarters,' whispered the TARDIS, a giggle behind the psychic words injected straight into Rose's mind.

Rose was still abashed from the Doctor's wording mistake a few moments ago, but she was intrigued at the amount of money offered. "Twenty?" she repeated into the steam of the shower, sure she had heard wrong. The TARDIS answered with a pulse in the water on her back, unclumping the mud in her hair. Rose pushed her brows up and smirked. "Twenty quid, yeah? Feeling confident?" Rose asked, scrubbing her hands through her blonde tangles.

The TARDIS gave a growl of a mechanical chuckle, which Rose took as a clear Yes.

"Fine then. You're on."

After she was clean, and no longer spotted with bog mud, Rose stepped out of the shower and switched off the water, grabbing a towel from the rack against the wall. She swiped herself dry, before leaning over, wrapping the tower around her hair and scrubbing it dry. Rose then discarded the towel and eyed her clothes on the floor, grimacing at the mood soaked through her good jeans. The TARDIS rumbled impatiently, and Rose rolled her eyes, before depositing her filthy clothes in a laundry basket and making for the door.

Naked, still clammy from the steam of her shower, Rose pulled open the door and peered up and down the hallway, a sly smile working its way onto her face. You'd think it hard to feel like a diamond thief when you were starkers with damp hair, but it wasn't. Rose pushed her lips together and drew in a breath, before stepping out into the hallway and shutting the door behind herself, quietly.

Bare feet padding carefully on the metal flooring, Rose felt the familiar adrenaline of their challenge buzzing in her veins, and she forced herself not to chuckle. She had this down to a fine art, she was sure. Besides, what did she have to worry about? The Doctor was probably still in the shower, anyway - and if he wasn't, then he was busy deciding what to wear until his suit was clean.

Rose approached the hall that led into the console room, and grinned as she passed it. One landmark down, one more to go. The key was not to run, she had decided. Rose had tried running, once, but that only got her a mouthful of wet hair, a panicked Doctor shouting a query as to what she was running about for, and the sound of footsteps hot on her trail.

It was at this point that the TARDIS decided that she had employed the subtle approach for too long. She had very likely invalidated the challenge, but it was a small price to pay for a final victory. Rose had won each and every one of their bets so far, and for the human, this was a bet for twenty pounds, but for the TARDIS, it was a matter of finding a revenge worthy of the nearly two hundred pounds she had forked over to Rose over the last few weeks.

Unbeknownst to Rose Tyler, the Doctor wasn't one to linger in the shower when it could be helped - far too impatient for that. He'd rather be reading or thinking or tinkering than standing around under hot water, so the moment he was clean - and smelling like a daisy, if he said so himself - he hopped out of the shower, dried himself quickly and threw on the closest clothes he could find - an old green jumper from his big-eared, northern-accented days, only slightly too big, and a pair of warm, grey tracksuit trousers.

The Doctor didn't really bother to dry himself, causing the jumper to stick to his back in places, but he didn't mind - he was already growing antsy from standing still for too long. The Time Lord slung a white towel over his shoulders, in case his hair, wet and smoothed back, dripped at all, to keep his jumper from getting any wetter.

Once satisfied that he was as dressed as he would be until the TARDIS had cleaned his usual attire, the Doctor stepped out into his bedroom, marched through, and then burst out into the hallway, turning left for the library and taking a huge, running stride onward, before he'd even registered the other person in the vicinity.

Rose yelped out both in horror and surprise as the Doctor barreled into her, throwing off both their balance in a squeaking tangle of arms and legs. The Doctor's feet slipped out from under him as Rose's shin swept them backward, and he fell forwards onto his companion, arms instinctively flying out forwards, either side of Rose's blonde head to keep himself from head-butting her in the face when they hit the floor.

Rose hit the metal flooring with a loud smacking noise, and the Doctor landed atop her only a moment later, rather heavily - even though he'd hit the floor quite hard with his knee in an attempt not to land on her - causing her to wheeze out in surprise. The Doctor took only a moment to catch his bearings before he pushed himself up on his hands and knees over Rose and stared down at her.

Rose's cheeks had turned a perfect shade of pink, he noticed, not long before he noticed that her hair was still wet from her shower. The Doctor noticed the unusual vastness of smooth peach skin showing below her neck, and chanced a glance down to understand it, only to find that Rose Tyler was completely naked underneath him.

There was a moment of lost, tense, awkward silence between them, as the Doctor sharply averted his gaze from Rose's breasts and Rose cringed, wanting to curl up and die of embarrassment. Twenty quid, she cursed herself. She'd gambled against the TARDIS and lost. In the back of her mind, she could feel the ship howling in laughter.

"Rose," the Doctor slowly said, and Rose scrunched up her face as he said it, "… you're um …" he began, forcing himself to look into her eyes - and that only made it more awkward, he noticed - and clearing his throat nervously, "You're naked," he pointed out, swallowing the dry feeling in his throat.

Rose stared back at him, and opened her mouth to answer, but she stopped, and all that escaped was a humiliated squeak. She shut her mouth again and pulled her lower lip between her teeth, before she answered, "Um … yeah," in a tiny voice, shivering involuntarily as the loose fabric of the Doctor's jumper hung down and tickled her bare chest.

The Doctor blinked at her, and considered getting up - but if he did that, he'd be standing in the hallway with a naked Rose Tyler. As weird as it was, for now, she was at least partially covered by the physics of their position, even if it was a strange one. "Do you …" the Doctor heard the high pitch of his voice and stopped, before continuing, "D'you want to tell me why?" he suggested, doing quite a good job of hiding the panic in his mind.

Rose stared up at the Doctor, trying to find her words. She stared at him for a moment too long, causing him to shift uncomfortably, which caused the rough fabric of his loose jumper to tickle her again. She sucked in a sharp breath between her teeth and tried to shrink away from the Doctor, but that turned out to be impossible. "I was …" Rose tried, but she couldn't think of a valid answer.

'You ship dared me to run naked past your bedroom,' didn't really sound like a good explanation as to what she was doing near the Doctor's quarters. The towel hanging down from his neck tickled her bare shoulders as he stared down at her, and it was becoming harder to think with each passing moment.

"You were?" The Doctor managed to push up one brow, lowering his voice involuntarily.

Rose averted her gaze from the Doctor's eyes, finding it extremely hard to think with his ancient, beautiful eyes boring into her soul, but was only more distracted when her eyes found the expanse of chest revealed by the dangling jumper draped over the Time Lord's lean structure. Oh my god, Rose heard her mind squeaking, drinking in the sight. They were so close - her senses were suddenly all absorbed in aspects of the Doctor; the way he smelled, the sheen of his now blushing skin over hers, the subtle sound of his breathing …

Rose drew another sharp gasp at the thought that jumped into her mind, and tore her eyes away from the Doctor's chest, looking back up into his expectant eyes. "Towel," she chirped loudly, speaking before she'd considered her words. The Doctor kept his brow arched at her, not understanding for a time, before Rose elaborated, "I was … looking for a towel," she lied desperately, not even bothering to fake a smile.

Something about the way the Doctor watched her told Rose that he didn't believe her. His tongue darted out of his mouth and licked at his bottom lip, and Rose felt as if her cheeks were going to burst into flames from the heat building in her face. She also felt a burning need to disappear to her room and lock herself there for a few hours until she was no longer distracted by thoughts combining the word 'Doctor' with the word 'Naked'.

"But your hair's not dripping," the Doctor inferred slowly, his voice slightly accusing. Rose cursed herself for quickly towel-drying her hair earlier. To illustrate his point, a droplet of water dripped from some hair dangling before the Doctor's forehead, right into Rose's eye, causing her to quickly squeeze it shut. "Oh, sorry," he said quickly, as Rose reached up a hand to wipe her eye.

As she did so, her hand blindly made contact with the Doctor's chest, tickling him as it did so, and sending a shiver down his spine. Rose wiped her eye and then stared back at the Doctor, still blushing furiously and trying to come up with another lie. The Doctor was quite interested to find out what Rose had been doing naked in his little corner of the ship, but was also quite distracted with the proximity between their bodies.

"So?" the Doctor shifted again, his voice barely above a whisper.

Rose squirmed beneath the Doctor, unable to help it, each movement causing more friction against his jumper and the precarious placement of his knee between her thighs. She lifted her own knee in an attempt to maybe nudge herself into a more comfortable position on the metal floor, but only succeeded in accidentally pushing herself upward against the Doctor. The Doctor hissed in a breath through his teeth as Rose's body came into contact with his manhood, and Rose gave a spontaneous gasp.

"Sorry!" Rose apologized breathily, and squeezed her eyes shut, biting down hard on her lower lip. "I was just … I got lost," she cringed at herself. She was never going to live this down - she was sure of it. "The TARDIS … usually puts my bedroom just across the hall," she explained, truthfully, too. But she was not about to tell him about her extremely childish and brazen bet with the ship that he had such high esteem for. According to him, the TARDIS was a magnificent being - brilliant and intelligent in every way.

And Rose had a feeling that the TARDIS would vehemently deny any such involvement in such a bet if the Doctor were to ask about it. The best thing was to just … not let the Doctor find out about any silly, girly challenges going on between her and the ship. It might make things awkward between them. Also, Rose really didn't want the Doctor to know that she had submitted to the dare - he might lose respect for her.

"Right," the Doctor swallowed thickly, taking in a shuddery breath. "Of course," he replied, quite willing to accept this explanation. "That makes sense," he exhaled a long breath that bounced off Rose's hot cheeks like swift, cool heaven. He laughed nervously, and Rose responded by discreetly catching her tongue in her teeth and tensing her jaw, her back arching slightly.

The Doctor looked down, wondering what that was about, and realized that the fabric of his jumper was quite present against her nipples - which, he could tell, were erect against the outside of said fabric. The Doctor felt heat creeping up his neck and onto his face, at the realization that each time he moved, the jumper was sliding tantalizingly over her breasts. Testing, he drew in a slow breath, tasting the air. He could taste the pheromones in the space between them, sense her arousal, feel the heat of her skin radiating off her.

It was intoxicating.

"I um …" Rose began on a breath, trying to find words, and this time, the Doctor could hear each and every endorphin racing through her, annunciating her words with a deep, sultry tone that he was sure she didn't mean to employ, "Didn't mean to get in your way," she said quietly.

The Doctor felt his mouth going dry again. "No, no," he replied, still distracted by the intoxicating taste of the air between them, and finding it extremely hard not to move just a little bit, to see Rose arch her back that way again at the friction against her nipples. "I knocked you over, don't apologize," he said, and finally gave in to the temptation, sliding himself a little to the left. Rose's breath caught in her throat and the small of her back jumped off the floor again - he'd have thought her good at hiding her excitement, if he weren't paying as much attention to her as he now was.

Rose felt the toes on one of her feet curling over. It was getting increasingly hard to stay focused. Stupid bet, stupid dare. Stupid TARDIS. And she could hear the aforementioned ship bellowing in laughter, screeching in hysterics at the back of her mind - which didn't help matters.

She was naked - underneath the Doctor. On top of that, Rose didn't know how much longer she could keep up the casual conversation. The Doctor seemed to have made himself at home on top of her naked form - which sounded wonderful, but wasn't. She could feel herself moistening, just from the closeness of his body and an accidental tickle on her nipples. Rose was quite sure that if she didn't get away from him right now, she was going to embarrass herself further.

Rose's self control was much depleted, the Doctor noticed, the next time he moved, and she grabbed her lower lip in her teeth again, squeezing her eyes shut and forcing herself to be silent. The Doctor had paid attention to where his knee was situated between her thighs, and nudged it upward, only slightly - just as if he'd been repositioning himself on his knees. It wasn't because he wanted to further arouse her - far from it! He was just curious, was all. Yes. Curious.

The Doctor was just fascinated with Rose Tyler; with the rate at which her ability to hide her stimulation was disappearing, and the range of different mechanisms she employed to keep herself from making a noise that would betray her excitement. "Did you bump your head on the floor?" the Doctor suddenly inquired, casually, but kept his voice low. He didn't mean for it to come out so tantalizing.

Okay. Maybe he did.

Rose released her lower lip from her teeth and tried - desperately - to speak easily. "No, I'm … I'm all right," she replied, swallowing and opening her eyes again. Her eyes found the Doctor's, staring at her with unreadable depth and contemplation. She adjusted her position slightly, unconsciously pulling her thigh away from the Doctor's leg.

The Doctor gave a bright smile at Rose, shaking his head slightly - struck for the moment by the allure that a full blush brought to her face. He must not have paid close enough attention to her before. He'd always thought her beautiful, from day one, but up close, she was breathtaking. The Doctor shifted more of his weight onto his right hand - Rose shivered again - and brought his left to Rose's bare shoulder, where a droplet from his hair had landed.

He wiped the droplet away with his thumb, and a thought occurred to him. He wondered what the pheromones Rose was giving off would taste like on contact. Being the Doctor, not one to stand back and ponder when there were experiments to be done, he leant down and put his lips to Rose's skin, just beside where his thumb now rested.

Rose's eyes widened in surprise, and she trembled at the intimacy of his kiss. The Doctor captured the skin between his lips, and gently licked, tasting her. When he pulled back, with a thoughtful expression on his face, Rose stared at him with a blank expression. "Wh-what was that for?" she asked nervously, hyper-aware of the coolness of the air on the wet spot on her shoulder.

The Doctor grinned at her. "Just wanted to see what you taste like," he answered honestly, in a bright, cheerful tone, though his eyes remained dark and hooded. Rose blinked at him, swallowing anxiously, an expectant expression washing over her face. The Doctor continued, "You taste lovely," as his voice lowered again, along with his head. This time, he kissed the edge of her collarbone. "Mm," he mumbled into her skin, as his hand wandered down her upper arm.

Rose allowed herself to gasp out loud at the sensation, confused and extremely aroused. A hand caught the fabric of the Doctor's jumper and held it tight, not wanting him to stop what he was doing. She felt the Doctor's tongue dart out of his mouth and lick gently along her skin, inching closer to her neck as his hand found her elbow and his fingers slid across her skin.

"Doctor," she gasped, but then cursed herself, because he pulled his mouth away from her, meeting her eyes with a confused look on his face.

The Doctor swallowed, then chanced, "Sorry, is it … do you want me to stop?" in a slightly hesitant voice, carefully removing his fingers from her arm. He tried to pull back, but found that he couldn't, as she was holding onto his jumper. He stared into Rose's eyes, as they clouded over with desire.

Rose shook her head from side to side and pulled down on his jumper. "No," she replied in a hushed whisper, "Don't stop," she poked her tongue past her mouth and licked her lower lip. "It feels good," she breathed, eyes staring up into his as he hovered over her. She meant to whisper something else, but the Doctor's lips met hers and she pushed up against him before she could help herself.

For a moment, before she hit the floor again, she felt his hard chest against hers - far more pleasing than the sensation of the jumper on her nipples - and a hardening muscle against her lower belly that told her that the electricity in her veins was reciprocated. Rose breathed in the taste of the Doctor's mouth - she could find the faint floral taste of her body wash, along with the ardent appetite with which he kissed her; licking and tasting, teasing and prodding.

His fingers found her skin again, gliding up and down her arm in a tender caress, as Rose gasped air into the kiss, dropping her head back to the floor. The Doctor took this as his cue to continue tasting her skin, and he dropped back down to her collarbone, unable to decide for a moment whether he should nip and suck at her neck or move down to her breast. Rose released his jumper from her grip, and laced her fingers through the Doctor's hair as he captured a nipple in his hot, wet mouth to tug it with his tongue.

Rose was immensely glad that they were the only two people aboard the TARDIS, as she moaned out in pleasure, arching her spine and resisting the urge to wrap her legs around the Doctor's hips. She gave a pleased breath that may have held a 'god, yes' on it, and the Doctor slid his hand under her naked waist, pulling her upward.

The Doctor's mouth released Rose's hardened nipple to the cool air, bringing her to gasp both in surprise and disappointment. He met Rose's eyes with a bright grin, and leant back onto his knees, slipping both hands under her back and pulling her into an upright position. The Doctor caught her hand and wound his fingers into hers, before kissing her again.

"Come on," he murmured into her mouth, "Not on the floor - you deserve better than that," he explained between fervent kisses, as Rose discarded the towel around his neck and raked her fingernails tantalizingly against his scalp.

With that, the two quickly collected themselves to their feet and ducked back into the Doctor's bedroom, slamming the door loudly behind them.

A full three hours later, the two lay tangled around one another in the Doctor's bed, breathless, sated and absolutely exhausted. Rose was still perched over the Doctor, her head against his chest, and the Doctor had a hand lazily toying with the messy curls that her hair had dried in. With a delighted sigh, Rose reached for the sheets and pulled them up over her shoulders.

The Doctor allowed curiosity to wash over his face. "So, why were you naked in the hallway?" he queried, now having decided not to follow her earlier story of getting lost.

Rose grinned to herself and looked up to meet his eyes. "Would you believe me if I said the TARDIS dared me?" she countered, catching her tongue between her teeth in a pleased smirk. The answer she got surprised her.

"The great Naked TARDIS challenge," the Doctor drawled, rolling his eyes and chuckling underneath Rose. He shook his head and tucked a strand of Rose's hair behind her ear. "You have Jack Harkness to thank for that, then," he announced with an amused look on his face.

Rose felt herself laughing too. "No way," she negated in disbelief, putting her cheek against the Doctor's chest and looking up into his eyes. "I thought she was just being cheeky with me 'cause I looked into the time vortex," she mused aloud, a fingertip tracing tiny circles on his bicep where it lay at his side.

"Nope," the Doctor exhaled, closing his eyes slowly and giving an almost imperceptible yawn. "Course, when I caught Jack it was a lot less …" he juggled for a moment to find the word he was looking for, "… intimate," he finally settled on, giving a great big grin as he did so. He went on, his hand slipping out of Rose's hair to her bare shoulder. "Rassilon, I could get used to this."

Rose hummed happily in her throat and then gave a little laugh. "Tell you one thing, Doctor," she began mischievously.

"Mm?" the Doctor queried wordlessly.

"I reckon I need another shower," she grinned.

The Doctor's eyes were open in a second, and he grinned too. "I think I'll join you."