[ Briefly, he tries to force the knife, but gives up when it becomes obvious he can't.

He tenses when she leans, forcing himself to not struggle and only relaxes (just by a hair) when she makes noises like laughter.

His own breath is coming in gasps, but that's because he's panicking a little. After a few moments though he starts laughing too -- though it's not happy, or pleased, just . . . laughter to fill the air. ]