Of course, even with the "clever" Principal Yamamoto backing him up, Sogo Doma could have simply ignored him. But Katsura Kotaro was there:
"Hahaha, Sogo, I never thought you'd tell someone I was your honored guest. Just as I thought..."
Sogo Doma: -_-
No, he hadn't said anything at all...
Forget it. It was too late to say anything now. Katsura Kotaro was the kind of guy who would climb right up if you gave him an inch. Even if Sogo denied it, the guy would probably brush it off with something like, "I never knew you were so shy, Sogo..."
Rather than waste his energy on this guy, he might as well ignore him and figure out how to deal with Erina Nakiri and Kaguya Shinomiya instead. EMMM...
Fine, the real problem was still Katsura Kotaro. If this guy weren't here, Sogo could have come up with any excuse to send them away—though he had no idea why Erina Nakiri and Kaguya Shinomiya had come to Toyogasaki, surely they hadn't come looking for him to stroll around the school festival with them? Maybe they even found it awkward to be around him!
Katsura Kotaro, on the other hand, was different. Not only did he have a history of pestering Sogo, he had just entertained the wicked idea of making him cross-dress and become a "new human." Even though Sogo had made him understand that even new humans had things they couldn't do, that didn't mean he had given up on pestering him—
Katsura Kotaro was stubborn and difficult by nature. Fantasizing that he could get rid of him with some random excuse was definitely not going to work.
Come to think of it, ignoring him like this was fine for now. But ignoring someone required a certain technique too.