I adore this story. It's so sexy and fun, with all those gorgeous layers of maturity and wit. This Severus is fantastic - this in particular:

In his imagination, however, he alternated between fucking her six ways from Sunday and curling up on his worn leather sofa with her, book in hand as they read the days away. In short, Severus was smitten.

Because this ^ is so often what we see as being Hermione's main desires. Here they're from his perspective, and it's just the icing on a delicious cake.

I love it, I love it, I love it!