My younger sister is always nagging.

    Yesterday, I accompanied my younger sister to have the piano class. We went to Xindian to visit my younger sister's piano professor last Sunday. Before getting on the train, my younger sister went to Seven- eleven to buy her breakfast. She wanted to have a rice ball with nori and Korean spicy pork. However, I didn't want to have this kind of food as my breakfast. Thus, I chose One-handed food including its soup as my breakfast. At this moment, my younger sister started nagging. Because she considered eating this breakfast may spend her time on catching the train. Besides, she said that it's very difficult to have soup breakfast on the train. But, I thought I won't make those problems, and I won't waste her time to catch the train. I just wanted to eat some food that I prefered. Because yesterday was pretty cold, I just wanted to have some soup to warm my body. After my explanation, she still couldn't accept it. Then, she felt very annoyed and started nagging all day.
    I felt very sad about it. I tried to express my thoughts, but she insisted that she was right. At that moment, I was very furious. That's because I spent my Sunday morning to accompany my younger sister to have the piano class. I spent half of my time  on her schedule; however, my younger sister was very afraid that I wasted her time for having my breakfast.