Nick knows he needs Cassie--loves her--more than anything or anyone else in the world. But it's not until this moment that he recognizes that he wants her.
Steve's done a lot of stupid things in his life, but trusting Natasha isn't one of them. (Inspired by the recent spoilery pics from the Cap 2 set, so uh, speculation & spoilers for the movie with reference to those pictures.)
Bucky understands the rules when it comes to spy games and secret missions, but he feels like he was in stasis the day they gave out the decoder ring for relationships.
"Real isn't how you are made," said the Skin Horse. "It's a thing that happens to you. When a child loves you for a long, long time, not just to play with, but really loves you, then you become Real." ~The Velveteen Rabbit