Married woman Ai is immersed in a dreamlike three-day affair, indulging in carefree sex with her illicit lover, unaware that her husband is actually home. While she deepens her intimacy with a rugged, intimidating stranger, her husband returns unexpectedly after canceling his business trip. Intending to surprise his wife, he hides quietly inside the house—but when she comes back, he ends up witnessing everything. Suddenly, right beneath the bed where he's concealed—close enough to see but not be seen—an intensely erotic scene unfolds. Forced to watch the adulterous act he never wanted to see, he feels his heart race and his body betray him with an uncontrollable erection. This voyeuristic experience, raw and unsettling, captures every moment in real time. Hidden desires and primal urges buried deep within the affair erupt into reality, exposing the brutal truth of infidelity.