This is sweet! I've also thought about the theory that about John dating is not what he really want, I mean even in the show he dosen't care that Sherlock averts his dates, he loves Sherlock too much, he didn't even remembered that, when he asked to walk one of his dates dog, it was not that date he asked who had a dog, it was one he dated before her!
I know John's married to Mary now, but I still don't think he loves her as much as he loves Sherlock. I hope season 4 will guide John back to Sherlock.
Anyway, keep writing :)