He's half your age and getting a bowl of ramen in the middle of the day, you wouldn't reach for your scroll or anything like that unless you were under suspicion of doing something you weren't supposed to be doing, like being in a group of rebels. I think Ruro was reaching for some of this, but Matsuka's recent actions just help confirm what he was reaching for. I don't see how Takeo is a rebel just by talking to her myself, and he can't really prove it anyway, it's just paranoia from both of you.