Oh my god,this is so sweet:))

It would be great if Sebastian is able to do even a few lines on season six!

This is so perfect. How Dalton is Blaine's Jerusalem (to sort of quote Rachel Berry); the place he returns to. And that the blazer is what he's born to wear, truly; that putting it back on is special for him (as you describe here so well).
That this comes with its own history (his short rejection note, followed by Sebastian's answering one) makes it all the better. Sebastian's reminder, that he is still a Warbler (always was), is like balm to Blaine's soul (since Sebastian no doubt knows why Blaine's back, Warblers being huge gossips and all).

Canon - accepted!

If there was fanart of that I would die happy

Great to see you writing again. Liked this.

Aww