Your little sister is the one who loves her big brother the most in the world. She constantly declares her love and has even made him promise to marry her in the future. This sister of yours has a problem, though: her nipples are too sensitive. If someone's elbow just barely touches her chest, she gets so excited that she starts trying to make a baby right then and there. Overwhelmed by the pleasure, your sister reaches orgasm from her own nipples, while her brother (you), who promised to marry her, can only watch.
