Ah, this is a wonderful vision of one of my very favorite pairings!
Thank you for not forcing them into an OOC "sexy love-birds" mold. I can't imagine Snape not always being at least a *little* bit grumpy in private, and Minerva more than a wee bit *practical*. I think both of them are the sort of people who would always express their affection indirectly, as here, through a mixture of fussing over the other's health and grumbling about their habits. I love how you show this!
Also: Minerva being tempted to rumple Snape's hair! OMG YES. *g*