Sherlock will do anything so long as he can be a part of John's life.
He'll even forgive Mary for shooting him and nearly killing him.
She realises that she can do anything she wants to him because he won't dare tell John if it means disrupting their happy family.
- Part 1 of Dark!Mary
Sherlock can put up with anything, for John. Anything at all.
But even the great Sherlock Holmes has his breaking point.
- Part 2 of Dark!Mary