fine [fahyn] adjective, fin·er, fin·est.
1. John: Oh right. Do you have a boyfriend? Which is fine, by the way?
Fine. Oh yes, it’s fine. He’s just asked Sherlock his first and last direct question he ever manages to ask about his sexuality. He’s just made the presumption that Sherlock must be gay, asked whether he had a boyfriend, and then realized how possibly inappropriate that might have been. They don’t know each other; Sherlock doesn’t know that John’s absolutely cool with that sort of thing. John is being sensitive to the fact that Sherlock might think John is asking this because he doesn’t want to live with a gay man. His question could be misinterpreted. He’s not meaning to ask Sherlock to come out, he’s just curious about whether Sherlock is dating anyone. He means, I’m not a asshole, it’s cool. I’m just curious.
2. Sherlock: I know it’s fine.
What does Sherlock mean by this? He’s misunderstands John’s statement; John is trying to assure Sherlock that he’s not about to be judged or rejected, but Sherlock, as he frequently does, actually addresses the actual statement (it’s fine to have a boyfriend) and not the implied one (I’m not a homophobe). He knows there’s nothing not fine about having a boyfriend. I suspect he’s had this conversation before; people have encouraged him in this direction, I suspect. This is probably laying the seeds for Sherlock’s understanding that John is flirting with him.
3. John: Right. Okay. *laughs* You’re unattached. Just like me. Fine. Good.
I actually have no idea why John says what he says here, to be honest. It’s fine. No: better than fine: it’s good that Sherlock is unattached. It’s something they have in common? I guess so. John doesn’t find it particularly good or fine that he’s unattached, does he? He has been deeply lonely up until this point, we know that. Why is it good that Sherlock is unattached? He could be just…saying words because they just had an awkward moment, I guess. Random words. But these are very strange things to say to someone. Possibly he’s just spent a bit too much time on his own lately, he’s fumbling. But I don’t think so.
4. John: I’m just saying. It’s all fine.
Once again underscoring: whatever your deal is, that’s fine with me. I’m not an asshole. I’m not going to reject you. Sherlock reads John as flirting, but I’m honestly not sure what John’s doing here. He’s trying to reassure Sherlock that whatever he does, and whoever he wants in his bed, John is okay with it. Because he’s not a dick. This is the sort of person I am, he appears to be saying. I will accept you, and be your friend/flatmate, regardless of what you are or how you get off. He doesn’t say, I’m not a homophobe! My sister is a gay! Which is a blessing. He just wants to say, sorry I asked you if you had a girlfriend, I didn’t mean to presume. Whatever you’re into, that’s cool with me. I’m fine with it all.
It might not be flirting, but it’s quite a generous statement to someone we’ve already established gets off on crime scenes and is (apparently) a psychopath. I mean, what’s he trying to get Sherlock to confess? He wants to know about Sherlock’s love life, even from the very start. And he gets no answers. John’s fascinated by him. John finds himself trusting Sherlock immediately. And he sort of likes that Sherlock isn’t dating anyone.
No, it’s totally flirting. Sorry, John. Sherlock was right.
But it’s okay. It’s all fine.