1girl, Mio, silver hair, (eyes like pale topaz:1.4), (keep eyes half-closed and heavy-lidded throughout:1.5), (no rolled-back eyes:1.4), (no wide-eyed:1.4), (head tilted back:1.3), (small mouth open and gasping:1.2), (deeply flushed face and shoulders:1.3), (vision slightly blurred and dazed with sweet intoxication:1.3), (Mio's entire body bouncing and shaking rhythmically from intense thrusts:1.5), (intense hip-to-hip contact with onii-chan:1.3), (glistening wet sweaty skin:1.3), messy disheveled hair, outdoor hot spring at night, (white bath towel fallen away:1.4), (exposed small breasts and nipples shaking:1.4), sex scene, (rhythmic motion:1.4), (no zoom:1.5), (static camera:1.3), dim cinematic moonlight, soft shadows, (high frame rate:1.2)