いつもは気丈な姉が珍しくデートに行くことになって嬉しい反面、寂しくもあったのに後日、姉とデート相手とのハメ撮りを偶然見つけてしまって嫉妬と嫌悪にまみれながらも興奮を隠せない自分に気づきたくない弟だった

fanboxで高画質版とセリフなし差分を支援者限定で公開しています
https://www.pixiv.net/fanbox/creator/5294339/post/958194

A younger brother who was happy for his always tough big sis going on a rare date, but on the other hand was lonely, too, and later on happened to find a recording of his big sis and her date fucking and, although drenched in envy and hate, did not want to recognize that he couldn't hide how aroused he was.

A high res version and textless verison are available on fanbox for my supporters
https://www.pixiv.net/fanbox/creator/5294339/post/958194