A sweet yet taboo love betrayal story as my relationship with my best friend's girlfriend Karin takes an unexpected turn! After getting dumped and feeling down, I called Karin—my childhood friend and my best friend's girlfriend—to hang out and ended up drinking the night away together. Her kindness in taking care of my drunken self gradually stirred my hidden desires, leading us both into forbidden territory. At first, she strongly resisted, but eventually became passive. Even as she whispered "No, we shouldn't," her nipples were hard and her panties soaked with arousal. While I played with her breasts, Karin moaned cutely, climaxing again and again, driving my own pleasure higher. Soon, I thrust my big cock (self-proclaimed) deep into her throat, and she came once more. Her cries of "Don't cum inside meee!" clashed with her moans of "It feels so good!!"—I couldn't stop even if I wanted to. Finally, Karin whispered, "Just cum inside me... idiot," and those words completely stole my heart. A faint, happy glow lingered on her face, and I realized this secret affair would soon become an addiction.