Written by Orutakawa Teng’a’
For this one I’m going to use the Marvel Cinematic Universe up to “Captain America: Civil War” to explain how I feel Captain America could’ve lived a life after thawing out.
The Canon Events.
As the events we know happen, the interactions between Captain America & Black Widow seemed to be drifting together. No I’m not discounting that odd “Avengers: Age of Ultron” Brutasha flirtation. All of that will be present in the new canon.
My Fixed Canon
Sometime after Steve & Natasha go on the run after the Leipzig/Halle Airport battle; they’ll be warmth huddling in some cheap hotel room abroad. Of course, Steve will be focused on his lost love Peggy Carter. As partners Captain America & Black Widow will stay together more often than not for security’s sake.
Weeks into running from the Sokovia Accord violation hunters, something will happen between them. I believe it would be during another huddle for warmth when a comforting admiration for each other sets in. A week or two later a tactical kiss will become as intimate as it is tactical. One thing leads to another and they’re together as partners in all ways. This also means they deal with “Infinity War” & “Endgame” very differently.
The Brunette Sized Hole in my Theory
I am sure that Cap will never forget the love he had for Peggy, but now being with Natasha & having his new life, he can finally move on. Plus being a child of 1922 Steve would seal his moving on by putting that one and done kind of ring on Natasha’s finger. In all likelihood he might vault his treasured compass with Peggy’s picture in it to emotionally let her go so he can fully accept Natasha into that area of his heart.
Cap’s New Life Outlook.
With the Spy at his side, the Soldier will become a genuinely happier man especially when the Bird, the Assassin, & the Archer are around for visits/missions. When he’s not in the fray of things, he’d probably finish his list of things to do & be the patriotic man we all know him to be. In this version we might find Cap being quite the connoisseur of the vintage redux furniture, accessories, be the drill sergeant of sorts to any new Avengers as we saw at the end of “Age of Ultron,” but with even more baby-faced newbie Avengers.