After school, Mateo invited me to his house to study together. Out of curiosity, I wanted to take a look around his house. Suddenly, my feet stopped in front of a room playing lively music. I peeked in and saw his younger sister dancing seductively, her round hips swaying to the rhythm of the music, driving me crazy. Seeing my erection, she seemed excited and took the initiative to lead me into her room. Being in her adolescence, she had a high sexual desire and demonstrated her skills in hip-shaking and riding, which brought me extreme pleasure. In my heart, I silently thanked my best friend for giving me the opportunity to secretly enjoy his sister like this.