Questions about Sanshun When did Zhenxuan start liking Sanshun?

Sanshun made him laugh in the cake-making episode. He thought he was a person who was not qualified to laugh. There is also some implicit relationship with taking care of his brother's daughter. Some love is so inexplicable that it sublimates through sarcasm, attack and appreciation... In his eyes, Sanshun was just a joke from the beginning, because of his figure. . hairstyle. . There are also some actions.