Yometori Kazoku Shiranu wa Teishu Bakari Nari

Nao is a housewife who loves her husband and has to share the house with her husband's father and his two adult brothers. These three guys do not work and spend all the time lazying around in the house and having sex with Nao, when her husband is out working. She dislikes it, but keeps the secret from her husband, as she doesn't want a divorce... [Edited from a description by FHC]