Steve's mouth twists; yeah, there is a difference between good and okay, and clearly B took it to mean the latter. And Steve knows he's not okay.

"Well, I'm not planning on it," he says, probably not-very-helpfully, though his voice sounds a little concerned, a little confused. His arm snakes around B's waist - frankly, it pretty much always does that, when they sit close. It's practically an unconscious reflex by now, trying to keep him close, give him comfort. "You just said the Nurse won't do it as a punishment."

Which is good, because Steve's not exactly promising to never get in trouble. But it sounds like he won't be executed for causing trouble, if it's got to happen again. And he knows it might, even if things are quiet(er) for right now. "So I'll be okay."