KAORI's husband has an adult son from a previous relationship. Though they used to live apart, they've recently started living together. The family relationship is good, with everyone being considerate and creating a warm atmosphere. Her husband, though older, hasn't been very active sexually. Since cohabiting, their intimacy has drastically decreased, making KAORI slightly uneasy. Without meaning to, she finds herself increasingly aroused. One day, her stepson comes home while working out. By chance, KAORI notices through his tight pants an impressively large cock, so massive she can't believe her eyes. Later, she secretly peeks while he's bathing and confirms it wasn't her imagination. That night, KAORI sneaks into his bedroom. She pulls down the sleeping son's pants and is mesmerized by his breathtaking cock, gasping in awe. She intends to return to her room without waking him, but can't resist—she slowly starts sucking his growing erection. Waking up from the sensation, the son is shocked to find his stepmother deep-throating him. But KAORI, already aroused and wet, presses her pussy against him and takes his entire length deep inside. The intense thrusts and flanged head scraping her vaginal walls send KAORI hurtling to climax instantly...