Widow & Winter

'"And what about Banner?" Buck said offhandedly.
"Bruce and I made no sense." She answered "He is a man with anger issues who hates to be lied to, and I'm a liar."'
With Natasha Romanoff's energetic charisma, and Bucky Barnes' deadly quiet, they make for quite a couple.
When Nat chooses to let Cap and Bucky escape, knowing the government would come after her, she made a decision, but a far different one then the one the Winter Soldier made when he chose to leave Steve and the other outlawed Avengers, after regaining consciousness when Hydra was deemed to no longer be a threat, understanding he would never have a place among them, because while Rogers was the same age as him, Bucky hadn't spent those years frozen in ice.
And Nat and Buck both had blood on their hands, and neither of them knew how to fix it.