Goodness me this episode was an emotional journey.
Sherlock solving the case then going to Watson's room to lay in his bed to find some form of comfort, Sherlock's cussing and venting of the case when he realises its revelations would hurt Victor, the moments of intimacy when Watson's speaks about the last memories he has of his father and them laughing together at it, Sherlock revealing the guilt and suppressed memories he has of the principle and the self identity crisis he has because of it?
Ok well now that a thing like a NAME has been taken care of. I have been chewing on how willsherbert comes to be.
Will/Al probably is established pre-fall. This happens fast and early. Possibly before they've both graduated Eton.
Adding Sherlock...pre-fall would avoid some complication, since if Will/Al haven't discussed non-monagamy at all until Will ends up in America presumed dead for three years while pining for his other love interest...that feels more like love triangle less like polyship. Even if Will never does anything with Sherlock that sounds agonizing.
But then adding Sherlock pre-fall complicates the Plan and I don't think Will or Al would do that.
So my brain of course ADDS PEOPLE bc polyshipping is great. So what if it's pre-fall Will/Al and simultaneous Mycal, and that's why Will/Al is open in the first place? So then there is the fall and Will knows he's free to pursue things?
And then you just have four of them in an interconnected polycule type situation.
At least I don't have to worry about Johnlock, it's easy enough to say this breaks off when John gets married. [All of Oscar Wilde's quips about marriage at the time would say society wouldn't make them...but John is too honest I think. Only way it would keep going is if Mary and him were marrying to cast aside suspicion for the other. But Sherlock would already know about her if that were the case, I think.]