Authoranon here: when you say Johnlock ending, do you mean they ditch the threesome idea, but Mary is ok with Sherlock/John?

I am feeling ambitious. I'm going to try to write three separate stories, a nice repentant Mary who Sherlock just can't quite let go around though he has essentially forgiven her; a Mary who Sherlock can't trust but is staying there because John feels obligated with his child and neither John nor Sherlock know what she might do; and a Mary where John and Sherlock are biding their time until she can be safely removed from their lives and they both are fully aware of this (but not Mary).
Might be fun to play with my own, sometimes conflicting, headcanons.