Oh, well it's quite simple.
Hawk Eye was assigned to kill Black Widow, and Black Widow thought she could get some information out of him because he was a shield agent, so she slept with him.
And there was some fight against other people.
And that's what happened in Budapest
Oh God, I don't. The best thing about Captain America is that his romance was so special there will only ever be one. Or only ever SHOULD be one *hint hint*
I ship them because I feel like she reminds him of Peggy, since they're both strong independent women, and he's so sweet and polite unlike other men that she would fall for him too :3
Hawk Eye was assigned to kill Black Widow, and Black Widow thought she could get some information out of him because he was a shield agent, so she slept with him.
And there was some fight against other people.
And that's what happened in Budapest
It's really there.