ROYD-192 Even though she's a gal, my super shy stepsister has been getting sexually harassed by me every day and has become extremely sensitive and prone to premature ejaculation, cumming non-stop! She transforms into a perverted girl with an obscene face

Due to my parents' remarriage, I got a new stepsister. She doesn't assert herself much, easily goes with the flow, is weak when pushed, and accepts minor sexual harassment. Plus, she doesn't wear a bra at home! Taking advantage of her personality, I sexually harass her every day. Naturally, she should hate it, but she can't refuse, her nipples get touched more and more, and as she gets played with every day, she gradually becomes addicted to it. Eventually, my sister first expresses her feelings to me: 'Big brother, I want you to touch my nipples.'