Captain America #448
Sharon comes back from the “dead” and teams up with the Red Skull in order to save Steve and the entire free world. She has nothing left to go back to, no one left to go back for, because as far as she knows, everyone she trusted has betrayed her. She’s spent so long thinking that everyone has betrayed her that she still can’t quite forgive Steve abandoning her even though she knows rationally that he honestly thought she was dead.
And here she is, making the deliberate decision to return to everything she’s been betrayed by and has spent the past several years hating. Because she wants answers, and maybe because she’s finally found the one man she’s ever truly loved and has missed him despite hating him so much for so long.
This isn’t their first bit of snarking since Sharon has come back, obviously, but it’s the first time in a long time that they’ve been together, with no world in immediate peril, with no emergency forcing them to work together, but they decide to work together nonetheless. They don’t even talk about how they can help one another, they just discuss fighting moves to learn. Because Sharon understands that Steve is good enough that he’ll help her no matter what and Steve understands that so long as Sharon wants answers for what happened to her, he’ll be there to help.