My boyfriend and I have known each other for a while, so I often come to live at her house. My lover has a younger sister, Karen, although we often quarrel, but the two of us are really close. Today, my girlfriend said that she was going to travel with a female colleague in the company, and I didn't notice until I accidentally found out that she was in another man's car! Bringing an angry Jin home to find Karen sitting in front of the door. It turns out that she has realized this for a long time but is not sure. At this moment, Karen confessed her feelings to me, I didn't believe it, so I joked, made her take off her panties and pussy balls in front of me. Unexpectedly, Karen did it without thinking. Angry about my girlfriend's affair, I unleashed all my anger on Karen. If you're unfaithful, so am I. I treated Karen extremely harshly, blindfolded, handcuffed, strangled... But Karen accepted it all, without a word of reproach. That calmed my anger, making me calm down and realize that I had treated her unfairly. From that moment on, I gradually sensed Karen's love for me, and I wanted to reciprocate her feelings. When my girlfriend returns, I will definitely break up with her and date Karen.