A/N: For Rose Marion Tyler, 'cos it's her birthday today :D xxx

-x-

When It Just Happens

Part 1

And this is why getting drunk with the rest of the humans at the party is absolutely a good idea for a Time Lord who's in love with his best friend.

She tells him off for staring, but really, he can't help it.

It's not his fault. She shouldn't be wearing that, if she didn't want him to stare at her. It should, by rights, be mauve; it's so dangerous. But actually, it's black. It's the tiniest little black dress he's ever seen - well, at least, he's sure it would be if he'd ever paid attention to little black dresses before now. As it happens, he didn't realise he had an affinity for them until she came out wearing one earlier on.

So really, she's caught him completely off-guard and it is Really. Not. His. Fault. And if he's a little tipsy, that's all her fault too, because she insisted that he had to act the part earlier, and get pissed with the rest of the group; it's only fair, she said, that he gets a hangover too. Pfft. But fine; he'll do whatever she wants because she's Rose and she's wearing the sexiest dress in the universe.

"Doctor," she hisses, and he jumps, just a bit, in surprise at being caught again. She's glaring at him from across the small space between them. Or at least, he guesses she is; he's not looking at her eyes right now, rather her legs, and blimey, do they actually go on forever, because he's thinking he'd like to test out the theory with his tongue or something and wait, she's telling him off again.

"Doctor, stop it, will you?" she says emphatically, trying not to draw attention to herself. Epically failing, however, as everyone's staring at her already anyway. She really shouldn't be wearing this dress. He casts a glance around the room and swallows thickly, his jaw clenching tight. Damn. He's really not the only one enthusing at the thought of exploring the sensual curves beneath that tight, delicious, gorgeous

She heaves out a sigh and he watches, and then she smacks at his arm and grabs at his hand and she's pulling him out of the living room and into the kitchen and seriously, he's really quite enjoying it until she pokes him sharply in the chest with an indignant finger. She does it again, harder this time, and actually, he's changed his mind; he's still really quite enjoying it. Funny, that. He wonders whether -

"What, exactly, is your problem?" she asks huffily, interrupting his racing thoughts but making his racing hearts race even faster. "I know you didn't want to come to this party tonight, but you don't have to - "

He moves so quickly, with the intent and purpose of shutting her up with his mouth, but when he presses his lips to hers she jumps back in shock and the air that takes her place is not nearly as satisfying.

He pouts, his eyes crossing as he stares down his own nose, checking to see if his mouth is being normal or whether it's turned blue with that dreadful stuff he's been drinking; he's thinking if it has, maybe that's what put her off. But no such luck. He pokes out his tongue to observe that too, but it's still as pink as ever so he concludes she just doesn't want to kiss him, which is fine.

Well, it's actually not fine, it's really quite alarmingly heartbreaking, and a crushing feeling has set up camp in his chest but he's totally not going to let her see that, no fear. He grins like he's done nothing wrong, aiming for cheeky and drunk and not at all about to cry. And he ponders that wow; he's emotional when he's been drinking.

"What are you doing?" she gasps, clutching a hand to her chest in shock. Her eyes flicker over to the open door, and she closes it swiftly. Then, she catches sight of the hatch between the kitchen and living room, and leaps forward, closing that too.

His eyebrows are steadily rising and when she's apparently finished blocking out the rest of the party – which honestly, is absolutely fine by him, it's only full of drunken human twenty-somethings who all want a bit of Rose's attention, attention that they can't, or at least, shouldn't, have, thank you very much, she belongs with him now, and yes, he tolerates the domestic side of things now, enjoys it often, in fact, but it doesn't mean they all had to come around for Rose's twenty-first, does it?

Of course, it's really her twentieth but she missed a year remember, and yes, that was his fault so maybe he should be more yielding about this matter, but seriously, he just wants to take her to Belle Ariaa, the nicest restaurant on the other side of the sun, thanks, not bring her here where he has to share her and her black dress with all her old crew and her mum and her mum's crew, too. He's already been propositioned three times tonight, so he dreads to think how many of the young human men in the flat right now have come onto Rose herself, the birthday girl, the beautiful, brilliant best friend of the greatest time traveller ever -

He takes in a deep breath.

Anyway, it's not so bad now, because she's locked them all out, and the music's still loud but it's more of a dull vibration than a constant ringing in his ears, so that's better too. What's very much not better is the fact that Rose still doesn't want to kiss him, however.

She hoists herself up onto the kitchen counter and oh, why does she do that? She looks even more delectable now, and that's just mean, that's just cruel – like hanging a carrot in front of a donkey or waving a banana in front of a Time Lord then abruptly snatching it away. Like showing him something he wishes he could have, then staring at him, arms folded, as if he knows he's done wrong and can't have it anymore. Or ever.

He feels a bit dizzy, and clutches at the fridge for support, leaning against it and trying for casual instead of seeming like he needs it to hold his weight lest he falls over. She's frowning now, and that won't do, especially as there's two of her, slightly blurry; and two Roses scowling at him is bad, bad bad bad, oh but not that bad, not really, it could be worse, but still, it's a bit bad, 'cos both Rose's should be happy, not frowny...

"Doctor, are you alright?" she mumbles, and he hears her voice in his ears but only just, like she's a great distance away instead of right in front of him. Right in front of him. Right in front of him, where he could just pitch forward and kiss her again, except he can't, because she doesn't like that, apparently. Hmph.

"Doctor?" she repeats, and she leans forward, which is kind of good but not; two sets of Rose Cleavage is fairly nice, but not when he can't have it, so now he's sulking instead and does not reply.

He squeezes his eyes shut and exhales roughly, wondering if he's ever found it this difficult to stand up straight before.

She grabs his hands and pulls him forward, and he opens his eyes and there's just one of her again. "Hello," he mumbles, wrapping his arms around her waist and snuggling into her hug that she hadn't really been offering but he'll pretend she was as his excuse. He's finished sulking and now just wants a cuddle to make him feel better.

She strokes his back and he thinks she probably doesn't mean to do it, or at least, it's just a comforting gesture. But it doesn't feel like that, not to him, and his spine's tingling with it. He squeezes her middle to distract himself but that doesn't really work, and then he moves his mouth against her neck as he wishes her, "Happy birthday, my wonderful, beautiful Rose."

She laughs uncertainly in his ear at his affectionate remark and he pulls back and cups her face with his hands. "I mean that," he insists firmly, and she nods, believing him, and he's satisfied. Then he remembers something and pouts again. "Why won't you let me give you a birthday kiss?" he grumbles, still cradling her head, his thumbs softly stroking the apples of her cheeks.

She raises an eyebrow. "That's what that was? Just a birthday kiss?"

"Yes," he nods emphatically. "Did you know, Rose, it's an insult to reject a birthday gift."

"The kiss was my gift?" she retorts, giggling. "I knew you didn't get me anything, you cheapskate!"

He drops his hands to the countertop and looks very, very put out. "Of course I got you something! But I can't give it to you here," he whines. "Or else your mother might kill me."

Rose grins, tongue between teeth and it's maddening. "What is it, then?"

"Well I can't tell you that, it'll ruin the surprise. But listen," he says, hushing his words conspiratorially. "I'll take you somewhere romantic and then you can have it!"

"Romantic?" she laughs, wrinkling her nose up. "You don't do romantic!"

He huffs, once again very annoyed. "Well I am going to this time, alright?" he grumbles.

She hides her disbelieving smirk and replies, "Alright!"

And then her eyes are widening and her mouth's hanging open and she's removing the hands he's just started to caress her thighs with. Ah. He thinks he's made a bad move again. Oh dear. Still, not his fault, remember! Totally her fault, honestly. Or maybe his hands' fault; they do tend to move of their own accord, sometimes, even with his rather excellent self-restraint...

"Doctor, seriously, does drinking alcohol really change you this much?" she giggles, keeping his hands still and decidedly not on her legs by entwining their fingers in the wonderful way they fit together so nice and snugly.

"Noooo," he denies, tilting his head forward to rest his forehead against hers. "Always want to kiss you," he admits. He nuzzles his nose against hers when she gasps in surprise. "Always want to touch you."

"Doctor?" she murmurs, unsure. She lets go of his hands and she pulls his face back from hers to look him steadily in the eye. "Doctor, you wouldn't be doing this if you weren't drunk," she states, sounding, dare he hope it, a little sad.

"No, but I'd be thinking about it," he retorts, and he wishes he had the confidence to tell her how he feels about her when he's sober, but he doesn't, he knows that, so he's selfish and decides to tell her now, when there's no ramifications for him. Indeed, when there's probably no way either of them will remember this come morning; she's drunk herself, after all, even if she's apparently handling the walking and talking thing much better than him.

"Because you are just so lovely, Rose Tyler," he continues, his hands finding their way back to her thighs, feeling the silky fabric bunch up in his fists as he slides higher; but she doesn't move them away this time, just scoots closer to the edge of the counter pressing closer to him and he loves it, loves her. "And I think you must know by now, quite honestly, how much I - "

The door slams open and he almost wants to die of embarrassment because he thinks it's going to be her mother and won't that be awkward, him with his hands almost, almost, so, so almost up her daughter's dress with him about to proclaim his love for her in the most unromantic setting possible. But then he breathes a sigh of relief, and so does she, because it's just two other amorous people trying to absorb each other in a snog, stumbling into the room and almost falling over each other in their passion.

Rose clears her throat pointedly and a girl, Shareen, her name is, he's pretty much sure, tears her mouth away from her bloke's and looks guilty for a split second, but then her eyes widen when she sees the position the Doctor and Rose are in and she shouts a triumphant, "Ha! I knew he fancied you really!" before her bloke drags her out of the room with a quick apology, shutting the door behind them.

He looks at Rose, then, and they both burst out laughing, but then the laughing is suddenly muffled because her lips are on his, yes, her lips are on his, because she is kissing him, or at least he thinks that's how it happens but maybe they just kiss each other at the same time, but it doesn't really matter because however it occurs they are kissing and it's glorious.

He's pulling her closer to him, hands slipping to her bum, and she's running hers through his hair and he thinks this - it's the best feeling in the universe. But all too soon she's pulling away, gasping for air as he's grasping for his senses back, no, wait, as he's grasping for Rose back, his hands now on her knees and wrapping her legs around his waist and he's tilting her back to try and reach her neck, her collar bone, the top of her chest with his lips and his tongue and his teeth and she moans, and –

There's someone calling for her, now, someone other than the Doctor, because he's just whispering her name over and over and over, not shouting it from another room; they ignore the unwanted interruption and she drags his mouth back to hers.

But then the calling gets louder, permeating their cosy little bubble of loveliness, and she's cursing under her breath as she pulls away and he thinks he quite loves that sound, too, but oh no, she's moving away from him, running a hand through her tangled hair, straightening out her dress, opening the door and he's left, alone, in the kitchen of her mum's flat, completely, completely missing her already.

His hands grip the edge of the counter and he breathes in deeply, trying to reign in some sense of control, some sense of –

She's back, then, not fifteen seconds later, having said her quick goodbyes to whoever was leaving just now, and this time there's dark, desirable promises in her eyes and she's taking his hand and leading him out of the kitchen and into her bedroom.

The rest of the party plays on outside her bedroom door while he and Rose dance alone within.