Only I know... Secret guide with my friend's mother

Hiroto has lived with his father since he was a child. She admires Rieko, the mother of a friend she always cared for, and eventually she finds feelings similar to her love... However, he is sexually ignorant, and doesn't know how to calm the excitement rising, so he finally talks to her. Although surprised by the confession, Rieko secretly explains to him... Hiroto, who is obsessed with the sensation he has experienced for the first time, can't hold it in and pushes her down, shaking his hips in a fluttering manner. Rieko gets cum many times by his merciless rhythm...