have already searched AO3 tags, google and the arc reactor tags in this community for this fic with no luck. i barely remember any thing about this fic, no author, no title, i dont think it was overly long and i dont think there was a big focus on the pairing, if there was any it would have been steve/tony. it must have been written after 'the avengers,' or at least after 'captain america, the first avenger' but definitely before 'iron man 3.'
the avengers were living together, either at the mansion or tower, all getting along, something, something, suddenly tony needs his arc reactor replaced, i think they're all togeher in the living room, and natasha volunteers to get the replacement coz she remembers where they are and she'll move the quickest. i specifically remember that she removes her shoes/socks/stockings to be quicker and she skids on the way back. she may also be called natalie in this fic. and that is all i remember, i know, pathetic!
if anyone can recognise the fic out of that mangled rambling, i will be so so grateful and so so impressed at your mad skillz
-found!!!!! i got some details wrong but the wonderful user marsmaywander found it anyway!! its a scene from chapter 13 of 'Off the Record" by goddamnhella http://archiveofourown.org/works/315889/chapters/1304460
hope that link works, thanks everone!!!