The Two Changes of Qing and Mo

"You dare to let my sister lose the baby in her belly. Do you know how sad she is? Fang Qingci, I will make you pay double the price!" "Then come on! The more you act like this, the more Si Xing will care about me. He will hate you for the rest of his life!" What on earth caused two sisters who were originally very good friends to turn against each other? How many lives are separated between them...