Bucky ran a cautious finger over the cool metal of the arm in the box, before shutting the lid and pushing it slightly out of the way. He didn't push it back towards Tony though, which was an indication that he would at least think about using it and he wouldn't argue about being given it any more.

"I'm sorry I left."

That needed to be said. Tony had relied on him for friendship, even if he had hidden it beneath bluster and hyperactivity, and Bucky had just bailed in the middle of the night and gone to ground.

"Everything was too much, and I needed to hide from it for a while. But-- I did miss you, god help me, so maybe we can keep in touch now."

It was the best olive branch he could offer.

Back in the other room, Bruce finished taking a blood sample before he replied, giving himself a moment or two to think. "What makes you think that there's something wrong with me too?" It's a very neutral question, he genuinely is interested in what Steve has managed to pick up on and if it could be an issue in the future.