第３話より
「初体験」を詳しく説明する内、かぐや様の反応に千花ちゃんの中のSの血が目覚めはじめ
話の内容はより過激なものへと変貌していく・・・

From the third episode:
As she explained what "first experience" means in detail, Kaguya-sama's reaction made Chika-chan's sadistic side start to awaken.
The topic of the explanation begins to turn even more extreme...