WRITTEN BEFORE SEASON 5!!!
Without altering anything canon up to season 4 (though the movies are kind of skipped over, sorry), I manage to completely rewrite everything that happened. No, seriously. And it all started based off of Discord's photo-bomb in Fluttershy's window during the season 4 theme.

What if, rather than leaving with Celestia after he was reformed, Discord ended up staying at Fluttershy's house, unknown to any of the other ponies? Chaos ensues. (Pun intended. )

Definitely a Fluttercord.

This story is a sequel to Spike: Lord of Disharmony and Chaos

Discord retired, yes, he retired from being the lord of chaos; and now Spike is his replacement.
With fresh new ideas and all the energy of youth, Spike is ready to make the life of the Mane 6 impossible; along with his loyal partners: the CMC

As all my other works, this is a translation. You can find the original in spanish here