This is all because of phipiohsum475. Have some Mycroft selfcest with bonus threesome:
NSFW teaser below the cut
Mycroft blinked and looked around, trying to get his bearings. It had been years, after all, but it seemed the experiment had worked. Now he had about four hours, if his calculations were correct. He set off down the street. Things weren’t quite like he remembered, possibly this was some sort of alternate universe? He mused over the probability as he went into a block of flats, wondering if this version of himself would still have the same address.
There was loud music coming from down the hall and as he approached the door, he realized it was coming from his own flat. Or what used to be his. He frowned and knocked. There was no answer, but judging by the volume, he doubted the occupant could hear him anyway. Taking a breath, he tried the door and found the handle turning underneath his hand.
As he pushed open the door it took another moment for his brain to register what he was seeing, then he tried to hastily exit, only for two pairs of eyes to stop what they were doing to look at him. This definitely wasn’t the him he’d been in his youth. This version of him was blond. And was that a tattoo?. Perhaps he should be more concerned that a very young John Watson was presently balls deep in this version’s arse. For lack of a better term.
“Can I help you?” His younger self was apparently unashamed to be caught in this state, as if Mycroft needed further proof that he was not exactly himself in this universe. The young man lay flat on his back on the sofa, naked, legs wrapped around an equally naked John Watson’s waist.