My serious younger sister suddenly came to me for sex advice! My sister, who wants to practice sex in preparation for her first time, and I, who am interested in erotic things, have aligned interests! But we promised not to go all the way until the very end... I accidentally inserted it! Moreover, my sister, despite it being her first time, was extremely aroused, so I rode the momentum and thrust hard, making her cum repeatedly! Since that day, my sister has become super greedy for sex and always wants to have sex. We have the best body compatibility, able to make each other cum over and over!
