It was hard to cause Steve more than a momentary flinch of pain, ever since the experiment. The slap of Bucky's palm against the back of his hand would have hurt plenty before, but now all it did was shatter his heart into a thousand pieces. Steve wasn't sure what hurt more, the thought that Bucky was dead and they were never going to see each other again, or that his best friend in the entire world had just denied every moment they had ever spent together.
Steve held onto his hand, nursing it as though the pain in his heart could somehow be transferred there. He wanted to run after Bucky, to tell him off for being so damn stubborn, but he couldn't. Instead Steve let him go, waiting until Bucky had turned the corner and was out of sight before he let the first tears roll down his cheeks.