SSNI-711 Wife Roleplays Cheating, Then Actually Betrays Husband in 3 Days

A husband with a wife in a rut, Shihori Kotoi, asks her to roleplay adultery, but she refuses. He then sets up his younger brother, who has feelings for her, and films what happens when he leaves on a business trip. Over three days, the wife gives in to the brother's advances, and the husband watches as their passion grows.