Colonel mustang had learned very quickly that the Fullmetal alchemist likes to pretend, that he didn't need anyone. Fullmetal had the distinct idea he had to prove himself to everyone and everything.
The boy was probably paranoid.
Still, Edward was bright like the sun and had guts. Not once had Roy heard Edward run from danger, he just would face it heads on.
Whether that was courage or stupidity was still the question. However, Roy had always found courage to be attractive in its own right.
Roy imagined that it was courage. After all, wasn't Fullmetal as strong as his steel limbs?
Still for all of Fullmetal's strength, Roy felt that he was still had to tiptoe around the matter. After all, Edward was still just a boy in all matters of the word.
Roy felt no reason to rush after all, if Edward was metal than he was fire.
Metal was always melted by fire and maybe it was enough.