Chapter I: a missing part of the end of A Scandal in Belgravia between John and Mycroft, before John goes up to Sherlock to tell him about Irene Adler's "end".
"Mycroft, has Sherlock ever been in a relationship with anyone?"
Mycroft raised an eyebrow.
"You mean, other than you?" he replied acerbically.
John rolled his eyes in response.
"Not that I am aware of, and believe me, I would know."
"Not even when he was at uni?" said John.
"No, he was too interested in correcting professors, boxing and chemistry to bother with women, or men," said Mycroft. "How do you think he'll take the news about Irene?" he continued.
"I don't know. I've only ever seen him around 3 women. He looks on Mrs Hudson as a surrogate mother. He had a weird intellectual flirty thing with Irene but I don't think it would have come to anything. And he's awful to poor Molly, even though she's mad about him," said John.
"Yes, well, he never quite got past the pulling plaits stage," replied Mycroft. "I'll be off now, you'll handle this Adler situation with Sherlock?"
"Sure, of course, why not?" John sighed.
Mycroft left, and John sat in Speedy's for a few minutes pondering how he would play this with Sherlock and also Mycroft's quip about little boys pulling the hair of girls they liked. Granted, his behaviour the previous Christmas was taking it too far but it was just possible. John resolved to observe more closely.