CAND-049 Let's show off lewd SEX to a gari-study sister!

My older sister, who I thought had no interest other than studying, had matured into a woman before I knew it. If you show such a sister a H act with her, will you blush? Or will my older sister, who I thought was a gari, get excited and act lewd…? [* There is some disturbance in the image and sound]