After the most recent episode, I basically just decided that (while in my fanon mind John and Sherlock fuck like rabbits) in my interpretation of them in canon is:
- John is a bi-romantic heterosexual
- Sherlock is a bi- or homo-romantic asexual
- They are in love with each other
- (and kind of in a relationship)
- Neither of them realizes any of this, because both of them base their interpretation of their orientation on the sexual side of it alone alone
So John keeps dating women, because he self defines as heterosexual, and keeps trying to assert that to himself. But because he’s monoamourous and is already in love with Sherlock, he just can’t make it work with any of the women he dates at all.
Sherlock, on the other hand, figured out he wasn’t interested in sex around the time everyone else in his age group got interested in it and he found the whole thing terribly tedious. He probably doesn’t even bother to self-identify as asexual, because he doesn’t even care enough about that sort of thing to bother labelling it. And then, because he’s already categorised any sort of couple relationship as sexual and therefore boring, and because he very rarely comes across anyone he considers worth spending any of his time with anyway, he doesn’t really realise he is capable of romantic attraction, either. He has so little experience of having friends that when John comes along he doesn’t have a comparison to realise that their relationship is romantic rather than purely friendship.
Which is why everyone keeps pointing out that they’re a couple, but both of them just react by thinking “No, because we’re not having sex.” rather than noticing that they are in love with each other.