C213 Causal cycle
The reason why Gai Cheng Hao needed his parents' consent was because he felt that his marriage could only be blissful with his parents' consent. Otherwise, even if he were to get married, his family would still be in a mess and he wouldn't be happy at all.
The next morning, when she woke up, Gai Chenghao said that her mother had been very pretty when she was young