[Yamaguchi stiffens, not quite imperceptibly. His expression looks suddenly guilt-stricken, but he tries to smile. He has no reason to lie to Tsukishima about this, why does he feel like suddenly trying to hide?]

Ah. [He fidgets, spoon chinking absently against the side of his soup bowl a couple of times.] …Um. This is gonna seem really weird, but…I'm kinda friends with Oikawa Tooru now, Tsukki? …He's been texting me a lot, so…