Shen Zichen remained outside. He could hear the crying sounds from the woman he had loved for several years. It broke his heart to see Li Xiuying like this and hated himself for not being able to protect her from the pain Mu Jianyu inflicted on her. However, he also knew that it wasn't his place to intervene. He was just a childhood friend who was secretly in love with her.
While he can be honest and clear with Li Chuntao, Shen Zichen found it odd that he couldn't tell everything to Ying. He couldn't pinpoint when he started having feelings for her and was scared as hell when it finally dawned to him what he felt for Li Xiuying.
But did it matter? In the end, he already lost his chance and she ended up being hurt.
Li Chuntao had forced him to look after her twin sister and he found it repulsive that she would ask something like that despite the fact that she was aware of his feelings for Ying. He could never understand women.