A/N: Originally posted on my A03 profile, SherlockianWhovian. Please review!

"Mummy has invited you and Sherlock to spend Christmas with her down in Sussex." Mycroft Holmes told John Watson as he sat in 221B, his umbrella at his side.

"And will you and Beatrice be joining us this year?" Sherlock asked casually as he sauntered into the living room, still holding equipment from his latest experiment.

Mycroft glared at his brother, silently warning him not to continue talking.

"Beatrice? Who's Beatrice?" John asked, looking between the two Holmes brothers.

"Beatrice is Mycroft's wife." Sherlock said simply, a smug look on his face.

"What? Since when are you married?" John asked, turning to face the older Holmes brother.

Mycroft sighed, "This is not a new occurrence. I have been married for years. Beatrice and I live apart and only ever see each other at functions." He explained to John.

"I'm sorry, I just can't believe this. You! Married! The brother who insists that caring is not an advantage." John laughed.

"Caring is not an advantage. I do not care for Beatrice. She is useful for certain work functions and that is it. Now, if you'll excuse me, I have to get back to the office." Mycroft said, getting to his feet and quickly leaving.

Mycroft hated Christmas. It was always an awkward and uncomfortable affair. This Christmas Day was no different. In fact, this Christmas Day was even more awkward than Mycroft had thought ever possible because Beatrice was sat beside him at the dinner table.

He'd been forced to bring her along after Sherlock had told Mummy that she would be attending. The two of them sat stiffly, clearly not used to spending time as a couple. Beatrice was tall, very beautiful and was clearly very intelligent. John spent most of his Christmas lunch watching the two of them interact. They talked and laughed together, showing very clear chemistry despite what Mycroft had told John.

"So how did you two meet?" John asked Beatrice as they went to the kitchen to get more wine.

"Through our work. It's top secret, of course, but I can tell you that I am an assassin." Beatrice replied with a smile.

"Oh, right." John said in surprise, clearly not expecting them to work together, "What's he like at work? Important and arrogant, I presume?"

Beatrice laughed, "You don't seem to like Myc very much. He can be fun and he, like Sherlock, has a wicked sense of humor."

"Mycroft has a sense of humor? I'll believe that when I see it." John chuckled, "You two seem to get along so well, why do you live apart? Why don't you just be a proper married couple?"

Beatrice sighed a little, "Our work is dangerous, John. Death is a regular occurrence. It is safer to be apart. Caring is not an advantage, it leads to weakness. By being apart, we are eliminating a weakness." She explained.