Well, that? That answers any lingering questions he had about whether or not Chase was really comfortable with this. House can't quite help the look he gives him at first, a mix of surprise and subtle amusement, because really it had had the desired effect - he'd broken through the young man's sullen refuse-to-talk exterior, even if what's underneath is sassy as hell.

"Brat," he calls him out, and if Chase wants it harder? Then harder is what he's going to get. The next blows are harder, not as hard as he's capable of, but it's giving him a taste of what's to come, back and forth from one cheek to the other. Maybe Chase isn't impressed still, but House isn't concerned about that. Maybe he'll push him for more, for harder, needle him about not doing the best he could - but House will get him to the point where he's not sassing back for more, but instead, squirming on his lap.