A/N: Okay, this started off as mostly a crack!fic from a Tumblr prompt, but then it got serious in the second chapter or so. Also, sorry for the disjointedness of this, but I figure memory is pretty disjointed sometimes, so, yeah.
Oh, and one more thing: Same-sex marriages are constitutionally banned in Nevada, but I decided to…overlook that slightly. It's more funny that way.
Disclaimer: I do not, did not, and will not, ship Johnlock. This just…sort of…happened.
John groaned and opened his eyes, squinting against the bright light streaming in through the window. He took a second to remember who and where he was – John Watson, in Las Vegas for a case with his idiot flatmate. He had a thumping headache, and the rest of him felt pretty crap as well.
He realised he had a massive hangover. The last thing he remembered from the previous night was going to a club, and urging Sherlock to have fun. After that, it was almost a blank. The occasional memory trickled through, however.
After a few hours in the club, John and Sherlock had had several drinks each, and were feeling rather merry. Even Sherlock was nodding absently along to the thumping music. John kept making eye contact with a pretty girl sitting across the room, who responded with a smile and a flick of her blonde hair.
John didn't know how long he lay in the hotel bed, feeling terrible. Eventually, he came to notice a weight on his left arm, which was stretched out to the other side of the bed. He flexed experimentally, and someone shifted beside him.
They were stumbling down the street on the way back to the hotel. The club had eventually closed, and kicked the remaining patrons out onto the street. Unfortunately, their journey back to the hotel was somewhat hindered by the fact that they were both too intoxicated to remember their own names, let alone where their hotel was.
Right. So he'd picked someone up at the club last night, and they'd spent the night together. Probably that girl with the hair flick. Why didn't he remember anything after the club, though? This didn't normally happen.
John 'Three Continents' Watson lifted his head and looked at the girl, preparing himself mentally (with the little part of his brain he had access to – the rest was preoccupied with his hangover) for the awkward conversation that always followed.
He wasn't prepared for what he found.
It wasn't the girl with the hair flick.
It wasn't a girl at all.
It was Sherlock Holmes.
John Watson was lying next to Sherlock bloody Holmes, hugging him.
And by the look of things, neither was wearing any clothes.
John looked up at the ceiling, then back across the bed.
Sherlock was still lying there.
A few minutes passed. John lay perfectly still, trying to work out whether he was awake or not. Besides, there was no point trying to move. Sherlock was a dead weight against his arm.
Eventually, Sherlock stirred, and began to open his eyes. Then he froze, staring at the ceiling. He was touching someone.
He rolled away hastily, unaccustomed to physical contact. He then slowly raised his head to peer over the pillow, to investigate.
He found John's face looking right back at him.
They stared at each other for a moment, then Sherlock cleared his throat. "Um, hello."
John flinched slightly at the noise. "Hello."
"This is…unexpected."
"Yes."
There was a pause, then they both spoke at once.
"Why-"
"Do-"
They stopped, then John said, "You first."
Sherlock frowned. "Are you wearing any pants?"
John lifted up the sheet quickly to check. "Yes. You?"
"Yes." He didn't need to look, instead jumping up and out of the bed.
John averted his eyes from his almost-naked flatmate. He tried to push his headache aside for a moment, instead asking him, "Do you have any idea how…this…happened?"
Sherlock was pacing back and forth at the end of the bed, eyes closed. "I'm working on it," he told John. "Do you remember where we were last night?"
He frowned, trying to think. Thinking hurt. "Um, we were in that club together, and you didn't like it much." He remembered some more. "You'd been rude to that poor policewoman, at the station with Greg."
"Oh, yes," Sherlock said, remembering a conversation they'd had in the club.
John had just stood up to talk to the girl when Sherlock distracted him with a question. "Was I really being rude?"
John stopped, and sat down. "What?"
"At the police station. Did the officer really cry because I was being rude?"
He frowned. "Well, yes. You were. It's…it's the way you say things, you don't stop to consider how others are going to take it. How it's going to sound to others."
Sherlock glared at his glass thoughtfully. "Hm. For that, I'm going to buy you another drink."
John shrugged. It made drunk sense.
They both cringed at the memory. "So, what exactly happened last night?" John asked. "How the Hell did we end up like this?"
"I…I don't know," Sherlock admitted. "Like I told you, I dislike being under the influence of anything."
John just nodded, closing his eyes and lowering his head gently onto the pillow. Sherlock kept pacing along the end of the bed, one hand to his forehead. "Think," he urged himself.
John just groaned, trying not to think too much. Thinking hurt.
"It just doesn't make sense," Sherlock explained. "We wake up, both in a hotel room, wearing nothing but our underpants. There's no evidence that anything happened, no smell, no…" He stopped abruptly, hitting his head with his palm.
"Oh," he exclaimed. "Oh!"
John blearily lifted his head by half an inch. "What? What is it?"
"John," Sherlock said, barely containing his excitement at having worked it out, whatever it was, "do you notice anything different about us?"
He snorted. "What, apart from the fact we woke up in a bed together, wearing bugger all, despite neither of us being remotely gay?"
"Apart from all that," Sherlock said dismissively.
John closed his eyes again. "I don't know. Can you shut the bloody curtain? It's like the temple of the bloody sun in here."
"Forget about the curtain, John! Your hand. Do you notice anything different?"
John raised his right hand to his face. "The other one," Sherlock told him.
He stared at his left hand dully for a moment, before looking back at Sherlock. "I don't see anything."
Sherlock was looking at John with a mixture of incredulity and pity. "You really don't notice anything, do you?"
"Well, no, not when my brain's trying to drill a hole through my…" He stopped because Sherlock had crossed the space between them in a bound, and was grabbing John's hand. "What are you doing?"
Sherlock pointed wordlessly at John's ring finger. To his surprise, there was a ring on his finger, a plain silver band that he had somehow not noticed. "What-" he started to say, before Sherlock held up his own left hand to reveal a matching silver band.
John froze, staring at his flatmate. He managed to find his voice in time to ask a question: "What does this mean?"
"It means, John," Sherlock said, reaching over to the bedside table, grabbing a document, and waving it in John's face, "that we are married."
John's blood ran cold. "You mean…" He didn't finish.
Sherlock attempted a smile, but instead looked more uncertain than John had ever seen him. "Hello, husband," he said cautiously.
Later, John wasn't certain exactly what had happened next. All he knew was that the next thing he remembered was opening his eyes, to find Sherlock's face anxiously hovering a foot from his own.
John gasped, and sat up quickly, almost banging Sherlock's head in the process. Sherlock was considerate enough to draw back, leaving John some personal space.
"Are you alright?" Sherlock asked urgently, but John had a more important question.
"How the hell can we be married? Is that even legal?"
"Interesting," Sherlock observed. "You seem more interested in the legality of this than whether we are actually married."
John picked up on the 'if'. "Are we married?"
In answer, Sherlock held up a sheet of paper, which John recognised as a marriage licence. His eyes scanned the sheet, flying to the bottom, where he saw two signatures that he recognised as his own and Sherlock's.
John's head fell to the pillow again. "How did this happen?"
Sherlock pursed his lips. "It appears we were highly intoxicated last night, and made a bad decision."
"A bad decision?" John choked out. "A bad decision? A bad decision, Sherlock, is saying something insulting by accident. A bad decision is putting eyeballs in the fridge without letting your flatmate know. However, marrying said flatmate is not a bad decision. That is a mistake on a massive scale!"
Sherlock looked away from John, over to the other side of the room. He was still sitting on the edge of the bed. "Can you remember anything else about last night?" he asked.
"We'll ROLL the old CHAR-iot along…we'll ROLL the old CHAR-"
"Ssssh!" John said, giggling at Sherlock while making a 'keep it down' gesture with his hand. "Be quiet!"
They walked along in the dark for a while, before coming across a lighted doorway. Sherlock noticed it first, who then relayed it to John amidst his giggles. They made their drunken way towards the door together.
"Nope," John lied. "Nothing at all. Why do you ask?"
"No reason," Sherlock said, still not looking at him. His fingers tightened on the duvet.
John sighed. "What's wrong, Sherlock?"
His jaw set. "I'm sorry, John," he said quickly. "I'm sorry that we got married. I'm sorry that you don't want to be married to me. I'm sorry that you must be disappointed, both in me and in yourself." He spoke as if trying to get the words out before anybody could interrupt. "I hope we can find a way to undo this and pretend it never happened." Sherlock stood up abruptly and strode to the other side of the room, staring unseeingly out at the street below.
John got out of bed and walked over to him, ignoring his pounding head. "Hey," he said, resting a hand on Sherlock's shoulder. Sherlock shook it off.
"Okay," John said, raising his hands and stepping back. "Okay." After a moment, he moved to stand beside Sherlock, also looking out at the garish lights of Las Vegas.
Neither said anything for a minute or so. Eventually, John spoke. "You don't need to be sorry, Sherlock," he said quietly, looking up at the detective. "I don't mind. We can sort it out. Somehow."
Sherlock stayed silent for so long that John began to think he hadn't heard him. When he finally spoke, John jumped slightly. "I need more data," he said, equally quietly.
He seemed on the verge of saying something else when suddenly there was a knock at the door, breaking the spell. They both jumped, and span around. Lestrade's voice came floating through the door. "Are you up yet? It's ten in the morning!"
John and Sherlock shot panicked looks at each other. "Whose room is this?" John hissed.
Sherlock glanced around. "Yours," he hissed back.
John cleared his throat. "Um, yeah, I'm up, Greg," he called shakily.
Outside, Greg Lestrade frowned. "You all right?"
"Yes," came the reply, perhaps a tad too quickly.
Greg frowned again. "Okay," he called back, unconvinced. "Do you know where Sherlock is? He's not answering his door."
Inside, John cast a worried look at Sherlock. "Uh, he's probably still asleep," he said cautiously. "Lazy sod."
Greg chuckled. "Yeah, probably." He glanced at his watch. "Well, we need to be at the station if two hours. Can you get him organised in that time?"
"Sure," John said. "See you then."
"See you," Lestrade said, and walked away.
John and Sherlock waited until they heard his footsteps disappear down the corridor, before letting out a breath neither had realised they had been holding. "That was close," John whispered.
Sherlock nodded vehemently. "Too close," he agreed. Then he glanced down at his left hand, and indicated the silver bands on their fingers. "We should take these off," he muttered.
John nodded also, and watched Sherlock slip the ring off cleanly. He tried in turn to slip his off, but it jammed when it got to the first knuckle. "No!" he said, wiggling the ring furiously.
"Here, let me try," Sherlock offered. He took John's warm hand in his cool one, and frowned slightly, concentrating.
"It's not coming off, Sherlock," John warned. "My finger must have expanded overnight. That, or the ring was too small in the first place."
Sherlock held his hand next to John's and compared his long, slender finger with John's shorter one. "It appears we got the same ring size, one that was too large for me but too small for you," he mused.
"But why?" John demanded. "Why did we even have these in the first place?"
Sherlock pursed his lips. "You're going to have to leave that ring on," he said, changing the subject.
John looked horrified. "I can't do that!" he gasped. "People will want to know why I suddenly look married!"
"We can easily deflect attention from it," Sherlock argued. "I won't wear my ring, and nobody will think a thing of it."
After some deliberation, John eventually nodded. "Fine," he said, sighing deeply. "Fine. But if we get found out, you can bloody well explain it, Sherlock Holmes!"
Sherlock nodded. "Of course," he said mildly. "Now, you had better go and wake me up before somebody notices that we spent the night together."
John winced slightly at the reminder.