Wow, I loved this! All that restraint and veiled language is so Snape to me. It was all so romantic and loving though at the same time. Every word you wrote seemed to highlight Snape's battle for self control but also the all consuming love he felt for Harry at the same time.
The conclusion was satisfying because it was so them! That slow friendship forming and then Harry's touches and Snape's concessions until it all came together beautifully. This is a really lovely story and some fantastic writing!