I love how you've worked the canon and shaped a future for the characters. Plus your way to tackle the Snape-problem was one I hadn't seen before. Both points are written well and believably and I liked that the stuff that happens after the war comes out gradually in the conversation, rather that it would've been storytold.
I love how Harry at 40 is still very much Harry, even though it's clear he's matured. (How could he not.) I love how IC they both are. I love their pillow-talk, I love the first paragraph, I love how the story is about a man going through hard time, and loneliness (I think), but manages to not be angsty.