[Jaskier first blinks at Julie, as if he's processing that he's actually startled her. And then he huffs.] My heart is perfectly fine! You're all treating me like a child. And I know you were not going to say "tamer," don't lie to me.

[He blows them all a raspberry because the lack of oxygen to his brain has obviously done a bit of damage in the moment, smoothing his shirt down and fixing the collar to where it's meant to be. And then brushing his hair out of his face, fixing the wayward strands.]

I'm not going to die, you know. Not in here. I've done much worse. [He sniffs.] Though now you mention it, [no one actually did] I am rather hungry. What about something sweet? That's a specialty of this sort of place, isn't it?

[Yes. He's clearly unbothered by the idea he passed out multiple times. Who wouldn't? It was exhilirating!]