A popular massage parlor, with only a thin curtain separating them from the other customers. In such a situation, a skilled erotic massage is performed. The woman must not let the person next to her know about the rising pleasure... While desperately trying to avoid the gap in the curtain, the sensitivity of the women is heightened to the limit, and they seek obscene acts. They choose "slow piston". Slowly and quietly... they start to move their hips in a pathetic, extremely slow manner so that the female customer next to them doesn't notice.