Teofilo Davila and his sister Segundo, confined to their small room, can't resist the heat building between them. They start masturbating secretly, but their excitement grows too intense to hide. Soon, they're openly pleasuring themselves, their eyes locked on each other's naked bodies. The tension builds as Segundo imagines Teofilo's cock filling her, and he fantasizes about her tight pussy. But a sudden knock at the door forces them to stop, leaving them both breathless and yearning.