There are a number of questions Pietro has, and he tries to push past the 'are you going to eat that?' question that intrudes the most. Instead, he looks at the other--really looks, and hums thoughtfully to himself.

"Then are you are not new to space, or the military?"

It's in the way he carries himself; the jaw mostly. That and he'd mentioned rations, so Pietro assumed it was a logical conclusion to come to. Or he could just be absolutely wrong-which happened a lot. It hurt his pride, but it happened.