Sherlock doesn't like birthdays.

Doesn't like celebrations, John Watson tells her with a wry grin.

But Christmas passes by merrily - Sherlock doesn't hesitate to kiss her under Mrs Hudson's strategically placed mistletoe, or sip on mulled wine and scoff mince pies while watching cheesy Christmas specials with her. He pulls crackers with her across the Christmas feast at the Watsons and smiles affectionately when she reads him the awful jokes inside them.

He counts down with her, three-two-one, at the Baker Street Hogmany party, and smacks happy, whisky stained kisses onto her smiling lips.

So, since she has deduced Sherlock isn't as averse to celebration as one would assume, she broaches the subject of his upcoming birthday. She waits until New Years Day, when they're stuffed full with Mrs Hudson's steak pie dinner and Sherlock is in a particularly jovial mood - which she discerns from the fact he's been very physically affectionate all night - and slips it in to the conversation.

"So…" she begins between slow kisses, her fingers toying with the shirt buttons she'd been dying to undo all dinner long. So much so, they'd snuck upstairs, claiming to their landlady they were in need of an early night. "I've been thinking about what we should do for your birthday," she continues, lifting her head so she can look into his blue-green eyes.

"Absolutely nothing?" Sherlock says hopefully, diving in to steal another kiss.

Molly breaks away, panting, giving him a pointed look not to try and distract her with unfair tactics. "We should do somehing," she insists, pouting a little for show. It's not as if she's asking much – she'd never plan anything too excessive – just a simple dinner or an activity of his choice. She was in no means the perfect girlfriend, but she wasn't just going to let his special day go by unnoticed.

"Why?" he asked, ignoring her glare and dipping his long, talented fingers under her dress and drifting them across her thighs. Unconsciously, she leans into his touch.

"Because," she argues weakly, as her evil boyfriend places open mouth kisses on her exposed neck, leaving a trail of goose-bumps on her flesh, making her mind go hazy and lose grip on her determination to see out this conversation.

Sherlock peers up at her, eyes gleaming dark and sultry. "Can't we just do this?"

Unable to resist such a tempting offer, she gives in; her fingers taking hold of his dark curls with intent, kissing him hungrily and her weak willed, hormone-fuelled brain insists to her that this has very much been a mutual victory.

Despite Sherlock's refusal of any 'official' celebration, Molly still organises with Mike to have a half-day. In anticipation of his arrival home that evening she curls her hair into pretty waves that flow over her newly purchased burgundy dress. The dress is simple – not overtly sparkly or colourful – but the material drapes over her petite frame in a way she hopes is appealing.

While waiting, she briefly wonders if Sherlock will be any less surly than he'd been this morning, dashing out with a hurried goodbye as soon as she dared to mention his birthday, claiming he was off to the Watson residence to seek out his doctor friend's help before she could even tell him about all the body parts she had stowed away in Bart's for him as a small birthday present. It stung for a moment – but she knew it wasn't a personal slight – he was just uncomfortable with attention that wasn't centred on him as the talented consulting detective, but just him, as Sherlock, the strange, wonderful love of her life.

But by six o'clock, she began to wonder if he would even be back this evening. That would be highly unusually, as he'd been endeavouring to work more 'sociable' hours of late, so he could spend more time with Molly and so John would have plenty of free time to be with his beautiful daughter and wife. The notion that perhaps he so desperately did not want to spend his birthday with her – even if it held little significance to him – spoiled the joyous, ardent mood she'd been aiming for.

When he did shuffle in to the flat just before seven, he has the grace to look guilty when he takes in Molly's effort; not only with her appearance, but how she'd cleaned and set up the table so it looked suitable to eat on for once. There was no heady aroma of food in the air; so he knew she'd been unable to begin cooking without an idea of when he'd be back, and his brows furrowed in remorse.

"Sorry…" he starts. His blue eyes, shining in the light of the kitchen, beg forgiveness.

"It's okay," she says, and it is, because she entered into a relationship with him knowing he wasn't the most considerate person on the planet. She is also aware he had many other brilliant qualities. "We don't have to do this if you don't want to. It's your birthday… if you want to go get fish and chips, I wouldn't mind," she reassures, peering down at her pretty dress, that's only really practical for indoors considering how chilly the weather is, and laughs lightly before continuing with, "I'll need to change in to something warmer though."

Sherlock smirks. "I think I'd rather stay here," he tells her, eyes drifting all the way from her dark hair to her burgundy painted toenails. "Let me help you make dinner."

Sherlock, it turns out, is a terrible sous-chef; who only distracts Molly with his intense staring when she attempts to complete even the simplest tasks. Even keeping an eye on her home-made pasta sauce is diificult with him gawping at her.

"Stop it," she chides, feeling her cheeks warming under his tender gaze.

Letting out a deep chuckle, he heeds her instructions, but only before pressing a lingering kiss to her temple, his hand momentarily a warm weight on her back, and then he disappears off into the living room. Without him distracting her, Molly has their meal finished in good time.

The dinner is all she wanted – intimate, romantic - but not overly so, as Sherlock doesn't seem to mind the candles and the soft music. Both can't help exchanging sweet smiles as they eat. Sherlock always seems to be seeking an opportunity to catch her eye or reach over to touch her pale skin. In fact, it almost seems as if he needs to touch her, his fingers drumming anxiously on the table when she lets go of his hand so she can clear away their plates.

Noticing his twitchy movements, when she settles back down on her chair, she peers up at him with questioning in her eyes. "You okay?" she asks, her thumb drawing circles on the back of his hand.

"No," he says simply in return, eyes swimming with some indefinable emotion. It almost edges on fear.

Molly's stomach drops. "No?" she echoes.

"There's something else I would like for my birthday," he responds, his voice shaking the tiniest bit.

This only serves to heighten her own nerves. "What's that?"

Without warning, he lets go of her hand, dipping it into the inside of his suit jacket and carefully places a black velvet box he extracts from it onto the table in front of her. Molly can see the movement of his neck as he swallows, and she lifts her eyes to find the alien comfort of his blue-green gaze. Desperately she tries not to hope, not to assume, because this is Sherlock…

"I would like for you to be my wife," he says, opening the dark box to reveal the contents, fingers shaking. Puffing out a heavy breath, he squares his shoulder and waits.

Molly's throat swells at the sight of the ring; the shininess of the silver is dimmed only by the tears filling her eyes, and it's glittered with tiny diamond that gleam brightly, completed by a large oval diamond at its centre.

"I – " she tries to force words from her mouth, but nothing else comes, because she's struck silent by sheer surprise. Finally, the words form, her throats clear, and she gives him the answer he is hoping for. "I'd love to."

Sherlock's eyes flash up to her, brows drawing upwards. "You'll marry me?" he questions, incredulous.

Molly giggles at his disbelief. "Yes," she says, nodding frantically and extending her hand out to let him slip the treasured piece of jewellery onto her finger. "As if I'd say no," she laughs, happy tears still threatening to fall.

Sherlock admires the way the ring looks on her finger, placing a reverent kiss on her hand. "I wasn't sure…"

"I could hardly turn you down on your birthday," she teases, gripping his hand tightly in hers, if only to prove to herself this is all real.

A grin takes over Sherlock's face. "I'd hoped not," he says cheekily. "Now we have a much better reason to celebrate this day."

"Oh, you clever man," she replies, getting up out her seat only to plop down on his lap, wedging herself between him and the table. "But there's no such thing as engagement anniversaries."

"There's not?"

"No."

"Oh."

Molly places a consoling kiss on his forehead. "And we're not getting married today, before you get any ideas," she informs him, her arms moving to hang loosely around his neck.

Sherlock scoffs. "There wouldn't be time," he rues. "We'd need a marriage certificate, my parents would need ample time to get to London, we'd need a venue, a cake, flowers… that would take at least a month. Maybe three weeks."

Stifling laughter, Molly presses a series of kisses to Sherlock's mouth. "Let's leave the planning to later, okay?" she suggests, beaming at her silly fiancé's thoughtful expression. "Because it seems, Mr Holmes…" she says, her lips barely a hair breadths from his, her voice deceptively innocent, but the tilt of her hips and the sultry look in her dark eyes are most certainly suggestive. "We have some celebrating to do."