As a Spike fan there is something that I and I imagine many other Spike fans have been waiting for for a long time.
Twilight Sparkle has grown a lot as a character. The once antisocial pony who treated friendship as a frivolous waste of time is now the princess of friendship. She has learned a lot about interpersonal relationships and is not only a great friend herself, she has moved on to teaching others how to be great friends as well.
She has grown so much in fact that in season five we were treated to Amending Fences; an episode written specifically to show the extent of that progress, in which she goes to make amends with all of her friends from Canterlot for her insensitive behavior towards them.
All, but one.
For as much as Twilight has learned about friendship, her treatment of Spike has barely changed. We get little moments of her validating Spike's feelings, like the time she told Spike that losing Golden Oak Library was hard for him too and apologized for not