Spoiler-ish* I thought the same thing, but before he finished his sentence, shishikura screeched and he started saying that his inside voice was really loud like that screech. Shishikura even says that he thought he was gonna say something weird, but he didn't.
Why the fuck did Kotani started talking about Shishikura's sexual life TO HIS DATE?
I mean I get that he was jealous and everything BUT IT WAS LIKE TOO MUCH???