[he stiffens at her words, which cut close to whatever semblance of a wall he tried to put up--between his feelings and how he wants others to perceive him. it's obvious there are cracks and it isn't built all that well in the first place.]

[eyeing the lunchbox that gave her such a hard time, he reaches over--despite her words--and tugs the zipper over the fabric hurdle, using a finger to push it to the side, allowing room for it to go through just fine.]

I know you're not happy with me, but I'm not assuming anything. [he looks back up at her.] I'm trying to do just that-- grow up. She has better chances of safely reaching the safehouse with you if we get spotted.

[perhaps, really, he's trying too hard, to an extent]