My mother lets out a lewd whisper

Hisayo discovers her son is holding a large number of dirty talk videos hidden. Feeling sorry for his son, who is angry at seeing his secret sexual fetish, Hisayo decides to give him one dirty talk sex as an apology. However, his son, who has become obsessed with the sweetness and excitement of Hisayo's words that are actually whispered in his ear, changes his promise and begins to seek fellowship over and over again...