I can't remember if there were any explicit pairings. Pepper and Tony's breakup may have figured?
I have no idea why I'm suddenly obsessing over this story, given that I didn't bookmark it at the time and it's been weeks since I read it. I'm 99.8% sure it is (or was!) on AO3 since I've barely glanced at any stories from anywhere else in this fandom. But now all of a sudden I am CRAVING it and I cannot for the life of me dig it up. I've tried every search on AO3 or via google site:search I could think of, to no avail. Hoping some fellow Tony-angst-lover might know. :)
ETA: Status as "found", and some more tags that seemed to apply. Hope I did that correctly.