Even as he moved to sit in a chair, the assassin narrowed his eyes and kept Stark in his sight. Although highly suspicious of the man and what he could and might do, he was confident enough that Steve could convince him to keep it to repairs and no modifications. They must have been fairly close allies if Stark was willing to do this despite what the soldier had done and attempted to do.

He only ignored the comment about favors and the strange nickname. Weapons didn't owe anything to the ones that repaired them.