お父様に内緒で限界まで拡げちゃいました～肛拡樓 参階

Mutsumi is a quiet girl.
One day, she finds an adult video that her father, whom she doesn't talk much with, owns.
What she saw on the video was a girl whose anus is being expanded with pleasure.
Since then, she started to be interested in anal expansion...

[edited from DLsite English]