1) Steve and Bucky keep ending up in the (Avengers Tower?) gym together, not speaking, just quietly using the equipment at the same time. Bucky keeps watching Steve working out via sideways glances/mirrors, until he eventually shifts the treadmill Steve's been using so it's (I think) in the middle of the room so he can openly watch- Steve comes in, sees the new placement, doesn't say anything but gets on it anyway. It's a weird dynamic between them, heavy with tension/build up and I think it ends up with them either making out or heading to their rooms for sex.
Found in comments: It's a Steve/Bruce story, rather than Steve/Bucky
2) Recovering Bucky fic, Steve had brought him some candy he used to love (I think licorice?) that Bucky doesn't trust to not be poisoned until Steve's eaten some, which he pulls a face at because he can't stand the taste of it but he does anyway for Bucky.
Found in comments, chapter 5 of this story