You do a great job of showing the gradual development of S and C's relationship, from stranger, to colleagues, to collaborators, to friends. It's very realistic. The last two paragraphs were particularly well done, with Severus thinking about what a pain Celia was, then wishing he could drink her tea blends more often.
Author's Response: This chapter made me nervous writing it, as it seemed like I might be compressing things too much. I'm glad to hear that it didn't come across that way to you and showed the transition. Thanks!