Husband, forgive me... Woman's Instinct by Namiki Tazi

Less than five years after their marriage, she and her husband lacked sex, making Yuuki feel very lonely but unable to express her feelings. At the same time, Noriko, her childhood playmate, was looking for someone to satisfy her sexual desires, and recently she fell in love with Oda, a masseur from abroad. One day, Yuki meets Oda by chance and falls in love with him...