Comments of chapter undefined of Do You Want to Marry Me?

I read a novel recently, but I forgot the novel name What I can remember was, that the mother was mistreating the daughter of her husband and his mistress wrongly. At the end, the husband confessed that he swapped his wife daughter with his mistress daughter because he felt resentful to his wife. He just wanted to see how his wife would abuse her real daughter and take care of his and his mistress daughter.