After being dumped by my girlfriend, I was sitting alone in my room, feeling miserable. Then I heard my sister's gentle voice comforting me. "It's okay... I'm sure you'll find someone better!" Her words made me feel a little better. Suddenly, she kissed me. "Would it be wrong if I became your girlfriend? I love you so much, big brother..." She whispered softly into my ear, then passionately kissed me, her tongue deeply invading my mouth. For a moment, I was too shocked and nervous to speak. Then, her lips began licking all over my face. She proudly showed off her slightly developed breasts, the kind she'd had since childhood, and guided my hesitant hand to squeeze them. The warmth and sensation stirred deep emotions within me. While my fully erect cock was dripping with saliva, she gave me an intense blowjob. Helplessly, I ended up climaxing inside her mouth, and she smiled as she swallowed every drop of my cum. Seeing that, I grew even more aroused. She exposed her pussy, glistening with arousal and covered in soft pubic hair. Right before my eyes, she began masturbating, refusing my attempts to stop her. Overcome with excitement, she climaxed repeatedly, then without warning, straddled me and took my cock inside her bare. "Big brother... watch me cum! Watch me closely!" Her words drove me wild, and we quickly found an incredible rhythm together—her orgasmic moans filling the room as she came again and again. Finally, she whispered, "It's okay, big brother... come inside me!" Unable to hold back any longer, I flipped her onto her back and unloaded a massive creampie deep inside her.