Ok, so I've been through all my bookmarks and practically all the Bucky/Steve works under the AO3 tag, and I cannot find this specific fic. In it, we're talking post-Winter Soldier because Bucky has his cybernetic prosthetic, and he and Steve are posing as boyfriends in an apartment building in (I think) Miami (and it's Miami cos it's hot and Bucky still has to wear long sleeves and roast in order to keep his left arm hidden). The two guys are there because some weird lights have been seen in the area and several SHIED agents previously on-site have gone missing. So, Bucky and Steve make nice with the neighbors and eventually figure out it's the daughter-in-law of one of the nice old ladies who lives next door.
I really want to re-read this story because I remember it being awesome, but I am simply having an impossible time tracking it down. Any help would be greatly appreciated!!! Thanks in advance!