50 Reasons to Have Sex #16 – Prom Night

"Mr. Holmes, Miss Hooper, thank you again for filling in at the last minute!"

The school's headmistress – no, wrong, she was the principal here, Molly still had to work at keeping the titles straight here in America – beamed up at the two of them. Molly wasn't used to people looking up at her, but Mrs. Leighton was barely five feet tall, a sprightly, genial septuagenarian with iron-grey hair and a perpetual smile. Even though Sherlock and Molly had originally come at her behest to investigate a troublesome drug ring that had infiltrated the staff – not the students for a change – she had never lost her cheery demeanor. Not even when the vice principal turned out to be the ringleader, along with several of the chemistry department staff.

"It's our pleasure," Sherlock answered the woman with what looked like a genuine smile. Molly smiled as well, and Mrs. Leighton wandered in the direction of the dance floor to reprimand a young couple who were a bit too engrossed in one another for public consumption.

The American high school was enormous – over a thousand students at the senior and junior level alone – and Molly was thankful it was almost time for her and Sherlock to go home. She'd never been away from the UK for so long, a full month now, and she missed her own bed. Of course, getting to spend time with Sherlock had been – well, not entirely fantastic, to be honest. Oh, some of it was, but the downtime as they waited for the drugs ring to make a move…a Sherlock at rest was not a pretty sight. She'd already known that, and was thankful that he'd not brought his handgun (or sought to procure one, which was distressingly easy to do in this country!), else the walls of their shared flat – apartment, she mentally corrected herself – would have suffered the consequences.

Ah, the shared flat. The main source of her joy – and her frustration. Sherlock rarely ate or slept when on a case, and if he indulged himself in any other way, apparently he put that sort of enjoyment off at the same time. Molly had certainly entertained a few fantasies involving the two of them become closer physically and eventually romantically during their stay in upstate New York, but their pose as brother and sister had quashed any public displays of affection, and Sherlock remained resolutely in character even when the two of them were alone.

Molly stifled a sigh as she fingered the diaphanous material of her bright pink prom dress. She had made the purchase on a whim, rather than simply pulling out one of her simple 'out to dinner with the faculty' dresses she'd brought with her. But when Mrs. Leighton had asked Sherlock for one last favor before they returned to London – to chaperone the prom in lieu of several of the now-incarcerated teachers – Molly had decided such activity merited a new frock, even if she was the only one who would appreciate it. And possibly Mr. Davidson, the technology teacher for ninth graders, who was constantly trying to chat her up and had been visibly relieved to hear that Sherlock was her 'brother' rather than anything that might be considered a rival.

He persisted in his attempts at asking Molly out even after she'd been revealed to be an undercover detective of sorts; if anything, it had only encouraged him further. Not that there was anything wrong with the man – aside from assorted habits and semi-questionable lifestyle choices Sherlock had taken great pains to point out to her – but he simply didn't, in the words of Molly's students, rock her world.

Sherlock, on the other hand…Molly stifled a sigh as she glanced at him out of the corner of her eye. He looked handsome as always, wearing a bespoke black suit, the collar undone, one hand in his trouser pocket as he looked out over the dance floor with a jaded eye. Why was it that the only time he'd ever seemed actually interested in pursuing anything other than friendship with her was when she'd been engaged to Tom? And even that day of solving crimes could have been built up in her mind to mean more than the simple 'thank you' he'd claimed it to be.

"Molly."

She started at the sound of her name, turned to give him a bright smile. "Yes, Sherlock?"

"A word in private, if you don't mind."

She furrowed her brow in confusion; why would he need to speak to her in private? They were practically invisible as it was, standing in the darkness on the outskirts of the dance floor while the mass of teenagers writhed and gyrated before them. She hoped he hadn't discovered some new case; she really did want to get home, to see how well Toby had behaved himself whilst staying with the Watsons, and to see for herself how much baby Isabelle had grown. Skype was fine, but it wasn't the same as the real thing, not by a long shot.

Still, she turned and followed Sherlock when he started walking along the back wall that led to the corridors the venue staff had used to bring the food and drink to the crowd earlier in the evening. The lights were so bright in contrast to the darkened banquet hall where the prom was taking place that Molly had to stop and blink for a moment before continuing on.

A warm hand caught hers, and she bit back a gasp of surprise as she realized Sherlock had not only waited for her, but it was his hand now holding hers. Their fingers intertwined as he pulled her rapidly along, and Molly wondered again what exactly this 'word in private' was about.

She didn't have long to wait; Sherlock pushed open the door to an unlit room far down the corridor; Molly had only a glimpse of what looked like a meeting room with a table and several chairs before he'd shut the door behind them and pressed her up against it.

Molly let out a squeak of surprise when she felt Sherlock's lips brush against hers, and she pulled her head away, pushing one hand against his chest. "Sherlock! What are you doing?"

"Kissing you," he said, his voice sounding huskier than usual. In the intimate darkness of the small room, it seemed to reverberate along her spine. A lovely sensation, but she was very confused and wasted no time in telling him so.

"I've wanted to kiss you for quite some time now, Molly," he said. She wished he would turn on a light so she could see his expression, but at the same time was enjoying the thrill of hearing his confessions in the dark. "And I know you've wanted me to, but we've been on a case, and you know how I feel about distractions on a case."

True, she did know that; he'd eaten and slept only when forced to do so the entire month they'd been here. "But why now?" she gasped as she felt his lips descend to her throat, his hands on her hips and his body pressed against hers.

"Case is over," he mumbled against her flesh. One hand slid up to cup her breast, and a flush of heat rose up her torso to her face. "Christ, Molly, this is the first real chance we've had to be together since my return from the dead, why wouldn't I want to take advantage of it?"

"This is…more than just…wanting to…kiss me," she gasped out as his fingers began to slide the narrow sleeves of her dress off her shoulders. Meeting resistance in the fabric if not in the wearer, he let out a grunt of frustration and reached around to ease down her zip.

"Well, of course it is," he said, sounding a bit put out. "Wanted to make love to you since I came home, but you were engaged to meathead and then I had the Magnussen case and you were quite angry with me about how I handled, ah, certain aspects of it…"

"You were using drugs and pretended to be in a relationship with Janine Mortimer!" Molly hissed in exasperation. She bit back a low moan as Sherlock's lips resumed their leisurely exploration of her skin, moving along her shoulder toward her clavicle. And when had her own hands started their own explorations, sliding along his chest and toying with the buttons to his crisp white shirt?

"And you were angrier with me about that than you are about my shooting Magnussen in cold blood," Sherlock pointed out, pulling his mouth away from her flesh and stilling the movement of his hands on her body. "But it was all in the same cause – stopping the villain and saving the maiden fair. Hmm," he added before Molly could say anything, "I suppose Mycroft is right, I do seem to see myself as a knight in shining armor at times."

"More like a git in shining armor," Molly muttered, but her fingers were still busy undoing the buttons to his shirt, and she smiled in the darkness. "Killing Magnussen – I didn't like it, Sherlock, especially when it seemed like it meant you were going off to your death to pay for it, but at least that part I could understand." She slid her fingers along his chest, pushing the front of his shirt aside and smiling again at the sound of a small gasp from his lips. His hands, which had slid back to her hips, tightened their grip, and she felt him move a step closer. "But risking your mind…"

"My beautiful mind," he reminded her in a low rumble just before his lips once again landed on hers.

She allowed herself a stifled giggle. "Your beautiful mind," she conceded, turning her head to allow him access to her throat and shoulder. Her dress hung from her elbows, and she shivered as she felt Sherlock's chest against her bra-clad breasts. He tugged at her arms, and she lowered them willingly, allowing the dress to slide completely off her body and puddle around her ankles. She stepped over the fabric as carefully as possible, quite pleased with the fact that she'd opted for thigh-highs rather than full panty hose, and once again wished for the light, if only to see Sherlock's reaction to her matching set. "But your risked that beautiful mind, and hurt Janine just for the sake of a case, Sherlock. You can't…ahh," she gasped as he removed her bra and lowered his mouth to her breasts, teasing her nipples with his tongue. She reached out blindly and groped for the waist of his trousers.

"Yes, yes, I promise never to do it again," he said impatiently as he brushed her hands away. She heard the sound of his belt being undone, the hook and then the zip, and listened for the whisper of sound as his trousers dropped to the floor next to her dress. She heard him kicking them away, then he his fingers were wrapped around her wrist, bringing her hand forward so that she brushed against his erection. "Can we please finish this discussion of my many shortcomings after we've had sex, Molly? We can't stay here indefinitely, eventually someone will come looking for us, and I really, really want to have you up against this door!"

His words sent a thrill up Molly's spine that originated somewhat more southward and towards the front of her body. She hurriedly stepped out of her now-damp knickers and undid the buttons on the wrists of Sherlock's shirt. He'd shrugged out of his jacket and she knew they must look a sight – both of them still with their shoes on, him with black silk socks and her with her silver heels and thigh highs and bra – but certainly couldn't find it within herself to care.

"Tell me this isn't a one-off," she ordered him as she felt his hands sliding around beneath her bum, preparatory to lifting her up so she could wrap her legs round his narrow waist.

"Definitely not," he replied with a grunt as he finished the maneuver. Molly reached between their bodies and gripped his cock, giving in to the urge to brush the tips of her fingers against its head, damp with pre-cum. Sherlock groaned and jutted his hips forward in an involuntary reaction to her touch, and Molly giggled before guiding him toward her opening. Normally a girl liked a bit of foreplay but Sherlock was right; this moment had been a long time in coming, and the last thing either of them wanted was to be interrupted by someone looking for the missing chaperones.

She gasped and grabbed at his shoulders as he pushed his way inside her. It had been years since she'd had anything but her own fingers inside her this way, and Sherlock, from the feel of things, was a bit more 'gifted' than Tom had been. She squelched the urge to further compare the two men; Tom was her past, and Sherlock had just pronounced himself her future, and there was no way she would ruin the moment she'd fantasized about for so long.

Especially since it seemed Sherlock was of a like mind. He pushed his way deep inside her and remained still, his forehead resting against hers and his hands holding her pressed close against him. As soon as Molly was ready, she shifted her hips and blindly moved her mouth to his, kissing him deeply. Then he was moving as well, a swift rhythm that brought her climbing toward completion within minutes. She moved her head and bit down onto his shoulder, letting out her breath in a hiss as her legs tightened around his waist and her orgasm pulsed through her body. He stopped moving for only a moment; as soon as she removed her teeth from his flesh – she hadn't bit down hard enough to draw blood, thank goodness, but he was bound to have a neat ring of toothmarks on his shoulder for a few days – he started moving again, tucking his hips under and hoisting her slightly higher as he grunted and gasped, indicating that his own completion wouldn't be far behind.

He gave a stifled moan as he came, and Molly sighed and rested her head on his unbitten shoulder, sweaty and sore and more content than she'd felt in years.

Afterwards it was all fumbling for clothing and Sherlock apologetically pressing his unused handkerchief into her hand for clean-up ("Next time we'll use a condom, Molly, I promise, even though I know you're clean and have a birth-control implant, no sense in making you trust my admittedly faulty judgement in these matters!"). They slipped out of the room and down the hall to the ladies' and gents' for a more thorough clean-up – Molly's hair was a fright but fortunately all she had to do to was tidy it back up into a bun and she was all set – and from there back to the prom. The dancers were still on the floor, or at least the crowd looked no-less thin, and they returned to their appointed spots on the fringes with none the wiser.

That is, they believed that to be the case until Molly saw Mrs. Leighton giving the two of them a knowing look as she strolled past, deep in conversation with her temporary vice principal. She gave Molly a wink and a smile and kept on going.

Molly blushed bright red, and felt Sherlock's silent laughter as his hand sought hers. "Busted," he said succinctly, squeezing her fingers lightly before placing his arm round her shoulder.

"Your vocabulary is becoming shockingly American," Molly teased, then shivered as he brushed his lips across her temple.

"A small price to pay," he said, giving her a smouldering look that weakened her knees. "Don't tell me you don't like it."

She responded with a quick kiss, and was rewarded by his arm tightening across her shoulder. "How much longer is this ridiculous party going to go on?" he muttered, glancing at his watch with every sign of impatience. "Damn, three more hours."

Molly said nothing, simply smiled and rested her head on his shoulder. Three more hours here, then a half-hour's drive to their rental flat – apartment, she'd never get used to calling it that! – then bed and an early flight home.

Even if she didn't get any sleep before boarding the plane, she didn't care. Not when she'd finally gotten everything she'd ever wanted – no, that wasn't right. She certainly wanted more than a quick (if satisfying!) shag against a wooden door. But the fact that Sherlock wanted more as well?

Yes, she thought contentedly as she listened to the too-loud pop music blaring and watched the youngsters dancing with abandon in the middle of the room, that was everything she'd ever wanted.

A/N: Yes, I know I already did a story in this series, but there were some leftover so I thought I'd take a stab at it! It is possible I'll follow this up with a teenlock version with Sherlock and Molly as overseas transfer students...we'll see! Enjoy!