Netorare kyonyû jukujo: Modorenai kaikan

Original title: 寝取られ巨乳熟女　戻れない快感

Directed by Shigeo Moriyama

Junichi is a web novelist and married to Rei. Junichi is struggling to come up with new ideas, so Rei suggests he try incorporating the opinions of his fans. They hold an offline meet-up, but Junichi ends up having an affair with one of his fans on a whim.