Without any regard to the blue-haired boy's first sentence, the so-called Skylark stayed where he stood. Normally, if the Little Boy had just been another student resident, Kyouya would have let it go-- maybe followed (stalked) the other down the hall a bit, just to make sure they really were doing as they said, but otherwise nothing. He wasn't a bully- bullies were, like he'd said, against the rules- but he wasn't going to be the nicest person another could run into late at night.
But Nata wasn't a normal resident. Hibari didn't quite like the idea of targeting a person based on which group they hung with, but it was effective, and the Prefect did enjoy effective ways. "Then why are you heading down that way." Another command, no verbal question mark added; it was like he expected the other to answer, no matter no.