Des:After a date with her boyfriend, my sister came home feeling depressed. Frustrated by failed sex, sister shows her bravery by stretching her vagina. I found my sister masturbating like this every day... At the limit of my patience, I said, This is because it will expand, making it easier for my boyfriends big cock to enter... and practiced sex with my sister every day! Gradually, although the younger sister had just practiced, she began to experience the joy of brother-sister sex...Unconsciously, the brother and sister began to have sex that was even more difficult than what they had practiced.