What the hell is that supposed to mean? Jaskier's fingers slow down with each of Geralt's words, frowning as he tries to put together whatever bullshit his witcher logic has came up with this time. Yes, Jaskier wants to yell, Eskel is very good at being there. He's only known him for a couple of days but his new friend has proven not to shy from Jaskier's various emotional moods, even if he does tense up when his witcher instincts don't know how to react to certain things. He accepted the word friend without hesitation. Yes, he has plenty of fodder for songs indeed, because he isn't stingy with the details.

They're truths, but also petty thoughts, things he wants to say just to hurt his heart's garroter the same way he hurt him first. But then Geralt adds the bit about spring, and Jaskier's brain finally catches on.

"...bloody hell. You are jealous."

The music comes to a full stop then. Jaskier wants to be offended at the mere thought of what Geralt is implying, but deep inside, he knows he would've done something very stupid if they had been in a town. Husbands and wives he may've bedded, yet he's never cheated himself - would've it counted as cheating this time, after he handed the brooch back? What are they even anymore? If they're something at all.

So no, he can't indignantly yell how dare you, I'm not a slut, because he knows what path that would take them through, and he isn't in a mood to defend his sex life. He's never made excuses for it since he left Lettenhove, and he isn't going to start now. So his anger attaches to be next best thing to be indignant about instead.

"Unbelievable! For you not to trust my word-- I was a fool, I admit, I should've expected that. But Eskel? Your own brother? You truly believe he would do that to you?"