It was Christmas. Christmas was Sherlock's favorite and Mycroft's least favorite holiday. Christmas meant presents, sweets, and fun for the little, five year old Sherlock. For the Nineteen year old Mycroft however, Christmas meant baby sitting a particularly excited Sherlock while their mother went to visit family and friends several hours away. Mycroft had already asked why he must always stay behind with the annoying child. The only answer he had received was, "Why should I spend the money for a nanny when Sherlock has an older brother who will take much better care of him?" He could not refute that statement, so baby sit he did.

By ten o' clock on Christmas Eve, Sherlock was running high on a sugar rush. He and Mycroft had spent the last four hours baking Christmas treats and, upon Sherlock's insistence, playing pirate. Now Mycroft wished simply that the little five year old would go to sleep.

"But Mycroft, if I go to sleep now I might miss Santa Claus."

"Sherlock, just go to sleep. You will have plenty of presents tomorrow without worrying about Santa Claus."

"But Mycroft, I want to stay up and see Santa. If I don't talk to him, how will he know exactly which present to give me?"

This was getting ridiculous, thought Mycroft, "Why don't you just write him a letter?"

"Everyone writes letters to Santa, I want to go one step further."

Why? Why must the child be so infuriating? Not that he hadn't done exactly the same thing as a child. He was just going to have to tell Sherlock what their father had told him.

"Sherlock, Santa isn't real. That's why you can't stay up to talk to him. Every year, mother or I put another present under the tree after you go to sleep. Why do you think I don't receive a present from 'Santa' every year? Because I'm too old to believe in the childish fantasy. You are getting too old for it too Sherlock."

"You're just angry, Mycroft, because Santa doesn't bring you presents. You said so yourself. He doesn't bring you presents because you are on the naughty list. You keep me from talking to Santa and then you tell me he isn't real. I however am on the nice list. I help you bake cookies, I try to tell Santa exactly what I want in person rather than through an impersonal letter, and I don't believe you when you tell me he isn't real."

"Sherlock, stop being an insufferable child! You are too old for Santa Claus. Now you need to go to sleep."

The dark haired five year old sat silent on the staircase for a few minutes. For a small amount of time, Mycroft had though that he had finally won. But, then Sherlock turned up towards his brother and said, "Fine then, Mycroft. You won't believe me and I won't believe you. I propose a bet."

"What kind of bet, Sherlock?"

"We stay up all night. If Santa appears, then I win. If he does not appear, then you win. The loser shall have to face a punishment. What do you say?" the small boy put his hand out as if to shake.

Mycroft indeed shook his hand. "What shall the punishment be?"

"I'm not sure yet, Mycroft, I have yet to decide."

"Well, you should tell me when you do. Until then, shall we watch a movie while we wait?"

"Oh, yes!"

And so they waited. Both of the boys, being as stubborn as they were, stayed up the whole night. During the night however, Santa Claus did not appear in any way, shape or form. Sherlock had lost his own bet.

"So Sherlock," said a triumphant Mycroft, "what is it that you as the loser shall do? Are you going to give up sweets? Not open your presents until tomorrow? Both of those would be rather fitting, don't you think?"

"I'm going to jump off the roof, Mycroft."

"What? Sherlock, you can't jump of the roof, you'll get yourself killed."

"A world without Santa Claus is a world I am not going to live in."

"But Sherlock, this is ridiculous."

"Goodbye, brother." Said the younger boy who headed up the stairs.

"Bloody, hell." Said Mycroft, who quickly headed up the stairs after his younger brother.

"Sherlock, stop!"

"No, Mycroft. I lost the bet. I have to do this."

"Sherlock," said Mycroft, who thought, I can't believe I'm saying this, "You didn't lose the bet. Santa Claus is real. I just wanted you to go to bed. I left a note for him last night saying that he had to hide the present with the others and not let you see him. I was just being a mean person when I told you he wasn't real."

Sherlock ran straight towards his brother and hugged him.

"I knew that was probably it. I figured that this was the only way you'd confess. But this means that you lost the bet Mycroft. Do you know what you have to do now?"

"What?" asked a very worried Mycroft.

"You have to come eat biscuits with me, every time I ask from now on."

"Ok, Sherlock." Said a very relieved Mycroft. Eating biscuits is not so bad.

"Every time I ask. From now on. Even when we're both grownups."

"Fine Sherlock. Even when we're both grownups."

"Ok. Now, come eat biscuits with me Mycroft!"

"Ok, Sherlock."

Twenty-two years later:

Come eat biscuits with me. –SH

Sherlock, I'm on a diet. –M

Every time Mycroft. –SH

Sherlock. –M

Every time. –SH

Why do you want me to come over, anyway? You hate when I come over. –M

I want to see if you still will. –SH

Sherlock, you know that Santa isn't real now. That means that you lost the bet. –M

Do you want me to jump off a building, Mycroft? –SH

Sometimes, I wish you would. –M

You'll regret saying that someday. –SH

I'll be there in thirty minutes. –M

Make it twenty. I'm hungry and I don't want to wait on you very long. –SH

Then why not go ahead and eat without me? –M

I'm not that rude. –SH

Twenty minutes, Mycroft. –SH

I have to work on getting you some friends. –M

Nineteen minutes, Mycroft. –SH

Maybe something more than friends. –M