My Elf Ball Contains My Sister

Luo Xingzhi has always known that his young and strong parents will definitely give him another younger brother and sister one day. I just didn't expect that my sister had grown so big when she was silent. "Don't worry, I will take good care of you in the future." Luo Xingzhi said gently to the little girl who suddenly appeared at home. In? How to deal with being mistaken for your younger sister by your childhood sweetheart?