Adult PC Game: Nozoki Seikatsu ~Bijin Oyako no Ana to Ana!~ by Tsuyudakukei Chichigumi Archive

Spy on women's secrets!
The hero was brought up in the city, lost his mother several years ago, and moved to the countryside to live with his father and his sister.
After graduating from school, the hero begins to help his father, continuing his work, and, ultimately, inherited his property.
And so the summer begins. Suddenly, the father's sister and her daughter, who lived in the United States, return. They asked to stay with the hero for a while.
Both mother and daughter have beautiful bodies and large breasts, so the hero quickly becomes fascinated by them.
"I want to look more at this body! I want to see that part of the mystery that was hidden! I want to learn more and more about women!"
This means that desire pushes the hero to "peep"!

Nozoki Seikatsu ~Bijin Oyako no Ana to Ana!~ by Tsuyudakukei Chichigumi Gameplay Preview