Kanojo no Okaasan ga Kanojo yori Attouteki ni Ii Onna de Gaman Dekinai!!

Yoshiki and his classmate Miki have recently become a couple. After their first sexual experience, he finally goes to her family's house to say hello. When he meets Miki's mother, Sayuri, Yoshiki realizes she is his true destiny. Fascinated by Sayuri's voluptuous body and adult sex appeal, Yoshiki can't think of anything other than having sex with her. When they are alone, he pushes her down without even a moment's hesitation, penetrating her ripe pussy with his thick rod!!

(Source: Otona Bunko, translated)