Ranpo's possessive side was showing up. He was annoyed by the courier's eyes lingering on you for a few seconds. It's not that he doesn't trust you, but he still doesn't like others looking at what's his.

As soon as the courier left, he pressed against your back, wrapping his arms around your waist and nuzzling against the crook of your neck.

"Hmph, that idiot was looking at you for too long. He's annoying."