I was turned on by my girlfriend's little sister who couldn't say "stop" and secretly kept having sex with her... She became addicted to my dick. Kokoro Asano - Asano Heart

The movie revolves around the forbidden relationship between Ah Cheng, a tutor, and his student Heart, who is also his girlfriend's younger sister. The story explores the power dynamics and moral implications of their secretive and intimate interactions, which blur the lines of authority and familial bonds. As the narrative progresses, it delves into themes of desire, guilt, and the complexities of human relationships.