The affection between parents and children.

Well, you can't measure others' kindness to you by your standards, can you? You always think what I did to you before. Look, you don't want to do this or that now, and I won't be nice to you in the future. In fact, everyone treats others in different ways. Maybe she won't give you a mobile phone or an iPAD, but she takes care of your life and cares about all your things (for example). Sister, that's the closest person in the world except your parents. I will always be good to my sister. Although my sister is much better to me than I am to her, she is the person I cherish most. I hope you will be good to my sister as always.