While living together in a small one-room apartment with my sister, who is still developing and very defenseless, I can't stop getting erections from her overly defenseless breasts and ass! My sexual desire keeps building up and I can't stand it anymore! Before I knew it, I attacked my sister, forced myself to insert myself and cum inside her! I've done something irreparable... I'm in big trouble! But then, my sister, who can't forget the pleasure of cumming inside her, started blatantly asking for my dick from that day on, and hinted at sex, so I got in the mood, and I became so obsessed with her that I cummed inside her many times!