I'm looking for the specific Stony fic. It's an old one. I think it's post-Avengers (it might be post-CAWS, but I really doubt it). It starts with Steve being increasingly annoyed during and after missions due to his Captain America suit being uncomfortable since SHIELD made it way too tight and now it’s chafing in the crotch area. And Steve’s physical discomfort builds to angry outburst during the after-mission debrief. Later Tony helps him with fixing the suit design problem.
I’d really appreciate your help in finding this fic.