A third of the time that Sherlock has company over it's someone trying to kill him. Another full third is taken up by Mycroft (who makes Sherlock feel like someone's trying to kill him, John's sure). The last group is made up mostly of people who are trying to hire Sherlock. John's not quite sure where in there to fit someone with whom Sherlock's cuddling on the sofa.
John puts the shopping (really just a handful of things he'd picked up on his way home from work) away and returns to the front room to find that that's definitely still Sherlock sprawled over another man. John spares a moment of gratitude for the fact that at least they're both still fully clothed.
"You can quit gawking whenever you want," Sherlock says, drawing back a little, with the effect of making it clear that he had in fact just been snogging the strange man in their living room.
"Sorry," John replies. "I was just trying to make sure I wasn't interrupting one of your more unusual fights."
The man lets out a snort without glancing over at John. There's a tweed jacket tossed over the chair that John's pretty sure didn't come from Sherlock.
"Not quite," Sherlock says, lifting an eyebrow as he runs his hands through the man's dark brown hair.
"No, I--" John's quite aware he's been gawking well past the point of politeness, but it's not like this is a situation he'd anticipated. "I don't suppose this is your boyfriend, then?" He's feeling entirely thrown, and Sherlock's casual straightforwardness isn't helping at all right now, but there's a level in affection in how Sherlock is handling the other man that John doesn't think could come from anything but a long acquaintance.
"It's been at least five hundred years since anyone's called me a boy," the man says, finally turning to face John. He looks a good five years younger than Sherlock.
Sherlock looks more than a little smug as he reaches out to straighten the bowtie around the man's neck. "John, this is the Doctor. He's a Time Lord, so the human label of 'boyfriend' is a falsely precise term and therefore doesn't apply."
John pinches the bridge of his nose. "Beg pardon?" That didn't make...any sense at all. He's very confused.
"He's my boyfriend, if that makes things clearer," the...Doctor volunteers, exuding cheerfulness.
"It doesn't," John says. "I'm sorry, I just...I thought you were asexual? That's...what I thought you meant."
"I am," Sherlock says, in his best 'get with the program, John, you're embarrassing me in front of someone who's actually reasonably intelligent' tone of voice. (It's not one that John has heard very often.)
"But you..." John trails off into a gesture that encompasses the whole...Sherlock snogging his nearly-boyfriend on the sofa.
"Asexual doesn't mean aromantic," Sherlock says primly.
"Fine. Then I thought you were aromantic as well," John says. He's spent enough hours on his laptop researching this because he didn't want to end up tripping over his words and making things awkward. He doesn't think he can be blamed for failing to anticipate that Sherlock has an alien boyfriend.
Sherlock just shrugs and rests both his hands against the Doctor's chest with casual familarity. "Not the case."
"Right." John nods once, slowly. "Sort of getting that." Pause, but really. "And what's a Time Lord?"
The Doctor laughs, apparently completely delighted by the question. "Alien. Really, I'm the last of the Time Lords, so generalizations don't matter."
"He travels in time," Sherlock says, and he sounds fascinated.
"Hence...the name," John ventures.
"Precisely!" the Doctor says.
"How long have you two been...going out?" John asks, because it's probably best to simply drop the parts of this that aren't making any sense, and possibly John did Mycroft an injustice when he decided that Sherlock didn't need a minder. Sherlock's clearly out of his mind.
"We mostly stay in," Sherlock says.
"Usually when people say something like that, they mean they spend most of their time having sex, Sherlock," John tries.
"Do they?" Sherlock seems to consider that somehow John's fault. "How idiotic of them."
John sighs. "Semantics aside..."
"It's been two years," the Doctor says.
"Five," Sherlock corrects, but with a 'I'm so brilliant' flash of a grin. It's weird to see the Doctor press a kiss to Sherlock's lips and even weirder to see Sherlock relax into it.
"Time travel?" John ventures.
The Doctor and Sherlock answer together. "Precisely."
"He's never mentioned you," John tells the Doctor, tension and the feeling that he's having the piss taken out of him making him short.
"You'd have told Mycroft," Sherlock said. "Do you have any idea how hard it is to hide someone like the Doctor from him?"
"No, I don't," John says.
"Very hard," the Doctor jumps in with, and he's not completely oblivious of John's anger the way Sherlock is, instead he's deliberately countering it with what seems to be entirely genuine exuberance.
"And so the two of you are in a relationship...without sex? And no prospect of sex?" John tries. He's not entirely sure he sees the point.
"I can't entirely see the point of sex," Sherlock says. "But I don't think my sexual life has ever been your business."
John throws his hands up. "You don't get to draw the line on this one."
The Doctor tilts his head, and for a moment he does look very alien (but in the 'cheap science fiction they couldn't even afford makeup but at least they got decent actors' type of alien). "Why not?"
"Because Sherlock's never respected my boundaries," John says, shooting Sherlock a glare.
"My boundaries never get in the way of a case," Sherlock replies, looking all self-righteously affronted, and John just...can't deal with that tonight.
"I'm going down to the pub," he says. "When I come back I plan to be sloshed enough that I won't be able to tell whether you're still here or have gone off to bed. Have a good night."
"You too!" the Doctor calls, and John shakes his head, and gets out of the flat while he still can.