Specific post-apocalypse fic

[morriganstears.livejournal.com]

Hello, all. I'm looking for a specific fic that I know I have read but cannot find in my 250+ bookmarks.

This one is set in either a roadhouse or diner. I think it is a diner. I can't recall whether Sam is Lucifer or just rules hell. The opposite applies to Dean (rules heaven or is Michael). I remember there is an old man in the diner who is the only not one freaked out by them walking in. He keeps telling the waitress/whatever that it will be okay. Dean(?) gives him some kind of message about a relative (maybe mother). Sam flips out when someone insults Dean.

I know this is really vague but it popped in my head the other day and I can't find it and it's driving me nuts. Sorry for how vague the description is.