I  read a Destiel fanfic two years ago that has stuck with me since. In it, Dean moves to a big city with Sam, who has a job at a bar where he meets Jess. Dean and Castiel meet at a dog shelter where Castiel volunteers. Castiel himself works with Anna and lives with Charlie (I  believe...). Dean dates Anna, but as he spends more time with Castiel wishes they were dating instead. There's a really poignant scene where Dean and Castiel sing "Hallelujah" together. I think the bar they work at is a central location for most of the characters. If anybody could please point me in the direction of this fic (originally found on AO3), I would be eternally grateful.