I don't remember much about this fic, except that it was Steve/Tony, Steve's POV, and there's a specific line that goes something like "Steve realized that Tony's slickest armor wasn't his suit," the implication being that it was his brain/wit/verbal defense mechanisms. It was also probably a post-Avengers, first-time, get-together type fic. I'm 90% sure I read it on AO3.
Thanks for your help!Aaaand nevermind! Because it was a fic that was just found--
(First Impressions Are) A Work in Progress--and that I actually had
open at the time. In my defense, I hadn't gotten to that part yet ;)