When I went to my friend's house to play, I found my cute high school sister wearing knee-high socks. When I got excited by the glimpse of her absolute territory through her short skirt and knee-high socks, my sister called me a pervert! A pervert! An idiot! But my sister was also at an age where she was curious about my erect penis, and even though she cursed me with words, she moaned cutely when we had sex.