Cal's not ready to go back in yet, and there's time, and the teachers have a tendency to pretend that this area doesn't exist. It's an unwritten agreement - they won't bust students for smoking if those students make it easy for them to ignore.

Cal feels like he's lived his entire life based on that kind of agreement.

(He won't draw attention to his father being a vampire if his father makes it easy for him to ignore.)

He takes out another cigarette.

"Not like it matters otherwise." As far as safety is concerned.