They hadn't initially began to drink together, no. John had actively avoided Mycroft for weeks after the Fall. He felt it was the only way he could restrain himself from beating the man to a bloody pulp. It was weeks until he felt that he had enough self-control to not attack the man when he saw him.
So he went to visit on a Friday, to see Mycroft drink whisky and, if John didn't know any better, he was sobbing; silently. A picture frame on his desk was lying flat. John walked over, Mycroft still hadn't noticed him.
John picked up the frame and looked at the picture. It was of two boys, the younger one wearing a pirate hat, brandishing a wooden sword, while the older one just smiled at the child. John didn't need deductive skills to know who the picture was of.
It was that day that John realized that when Sherlock fell, John might have lost his best friend; but Mycroft lost his little brother.
"Go ahead and yell; Dr. Watson" Mycroft's, slurred, voice said.
Instead, John took a seat.
"It wasn't your fault, Mycroft" John said as he placed the picture in its place, but upright.
"Yes it was, I gave my little brother's life story to the man who wanted to ruin him"
"No," John said "It is my fault, if I hadn't walked off, if I hadn't called him a machine," John's hands tensed at one of the last things he had ever said to Sherlock, before he continued "he might be alive"
Mycroft then look up at the man, broken like he was, before pouring a new glass of whisky. He handed it to John. He then filled his glass again.
The two raised their glasses, a silent toast to the brilliant man they had lost.
If he ever was asked, John would say that he would never have guessed; in a million years; that he would be having drinks with the British Government.
And yet, here they were. Every Friday, the two would meet and have some drinks. To ease the pain. The pain that was emitted by the silence.