Incest mother and child swapping

It's been several years since my husband took a mistress and stopped coming to my house. Yukari poured all her love into her son Shota. However, Shota was really troubled by Yukari's attitude. In fact, Shota was also made to be the night partner of his frustrated mother. One day, Shota reveals a secret to his best friend Kohei. Kohei then reveals that he also continues to have that kind of relationship with his biological mother, Sawako. Kohei then whispered to Shota. ``Let's have fun swapping each other's mothers''...