My mother is being raped by her son every night

My husband is on a business trip alone. Madoka lives with Taichi and Yoichi and her two sons. His eldest son, Taichi, is solid, but his second son, Yoichi, has not yet decided on his career path, so Madoka is worried about himself. One day... Madoka is unable to see Yoichi keeping playing with his smartphone without listening to others, and confiscates his smartphone... That night, Yoichi sneaks into Kumadoka's bedroom to retrieve the stolen smartphone. What I saw there was a different face to face in my mother's nightlife, as a woman, which was different from the daytime...