[Those words, sincere are not, ring nothing but false (impossible, even) in Yamaguchi's ears, after time and again spent hearing just the opposite. It pushes him past the edge of overwhelmed, into disbelief. From there it's only a quick, defensive flicker of thought to outright suspicion. His eyes narrow, and his hands tighten to shaking fists on the table.]

Stop it! [The words are louder, and higher in pitch than Yamaguchi anticipated. But he can't stop now and try again, or else his angry voice might crack instead.] Don't...say something like that, unless you actually mean it, okay!? Th-That's not fair, Oikawa-san!

I may not be as smart, or as good at volleyball, or handsome as you are. But, I definitely don't need anyone hanging out with me, who will lie about it, when they think I'm actually pathetic!!