A Good Many Family Trees Are Shady (Torchwood/Sherlock)

Rating: PG-13
Word count: ~ 6,600
Warnings: Mentions of canonical character death, canonical (supposed) suicide, and spoilers for all of Torchwood and Sherlock.
Summary: For a prompt on the Sherlock kink meme that grabbed me and wouldn’t let go. (The title pretty much says it all.)
Disclaimer: All recognizable characters are the property of their respective owners. I am in no way associated with the creators, and no copyright infringement is intended.
A/N: Um…the first part of the title from a quote by Robert Elliott Gonzales. Yeah, this is a bit weird and angsty; I apologize.

( Five Times Ianto Called Mycroft 'Tad' and One Time Mycroft Called Ianto 'Son' )