Okay, but like…
The Scene at the graveyard.
Whether you believe Sherlock himself ships it or not, clearly this—Greg and Mycroft, dealing with his shenanigans together, silently communicating about him and thinking he’s not seeing the looks—is something they’ve done before. Enough that it shows up in his mind palace.
Being conservative about it, even if you think he’s extrapolating that they WOULD do this based solely upon information he’s picked up concerning the way they are together, I just…
Happy new year to all Mystrade shippers everywhere.