[The Younger Sister Who Secretly Loved Me Went Wild with Jealousy After I Started Dating Her Older Sister - Mirei Uno]" I have childhood friends who are sisters. The older sister is in the same grade as me, and the younger sister, Mirei, is three years younger. When we were kids, the three of us used to play together often, but as we grew older, I saw less and less of Mirei. Eventually, the older sister confessed her feelings to me, and we started dating. I decided to share the news with Mirei and went over to their house. But something felt off… She wasn’t exactly in a celebratory mood. Her expression looked strained, almost like… she felt I had "stolen" her sister? Later, I was invited back to their house. And then… wait, what!? Mirei, what’s with that outfit!? "Hey, Mirei, what are you wearing!?" "Why? Isn’t it cute? It’s my house, so who cares?" Mirei appeared in an extremely revealing outfit, pressing her chest against me while locking arms. It was so blatant, I couldn’t even look directly at her. That’s when I realized— Mirei had feelings for me all along! Her strange expression before now made sense. Even with her older sister nearby, she would flaunt her cleavage, press her chest against me, and try to seduce me. I had no idea Mirei had matured so much… And then, one thing led to another. Initially, I gave in out of a fleeting moment of weakness. But Mirei’s temptations only escalated. Even while my girlfriend was drunk and passed out nearby, Mirei climbed on top of me, and we… I knew I was betraying her, but the excitement, the thrill of it all— I couldn’t stop. Mirei’s allure was overwhelming, and I found myself unable to resist.