This is a story about the first time I stayed over at her house. She has a younger sister who is a uniform-wearing girl with a face I like and impressively plump thighs. Isn't it surprising that her sister tried to seduce me with a glimpse of her underwear while my girlfriend was doing housework! Although I knew it was taboo to have a fling with her sister, I couldn't resist the temptation and dove into those thighs. By the way, my girlfriend absolutely won't do it without a condom, but her sister let me have my way without one (^O^)V.