My wife's own sister came to help with the household chores because my wife was hospitalized. Tsubaki-san, the husband's sister-in-law, is beautiful, good-natured, and caring, and she does a lot for her brother-in-law. They become intimate during their private time together... She is a married woman with a husband, but in his wife's absence, she engages in a series of intimate and lewd acts with his sister-in-law! She falls into the forbidden pleasure that must never be revealed!