With Thorin walking away, Fili could finally release the breath that he found himself holding in. Finally looking back to his brother, the blonde noticed the amount of shame in the brunette's eyes. Gently, he lifted a hand to the youngest's chin, and turned his little brother's face so he could see the mark that their king left behind on his neck. Even if the brunette stubbornly attempted to hide it, Fili effortlessly made the mark be in full view. He sighed sadly, though felt a little angry at this unnatural act. 

The blonde heard Bilbo's claim, and it left Fili a little confused. "Dragon Sickness?", he had never heard of such a term, looking to Kili for his input. However, he wanted to change the subject. "Did you find her, at least? Delva? Is she okay?", he asked.