My impression is that LiHuan is feeling sick because he can't know if YuYang will ever get over his one-sided love for LinZiang and ever consider him. It can feel like a real bad stomache ache, for real. That is just my impression. Its great he can cover and act like they are a couple but I don't know that he thinks it will go anywhere.
He's acting. When Luhuan said "I feel bad" meaning when he saw Yuyang being cornered like that he feels bad, but Yuyang thought he meant "I feel bad" as in he doesn't feel well. When Yuyang got concerned and starting holding on to him, he acted so that he can hold Yuyang a little longer.
My impression is that LiHuan is feeling sick because he can't know if YuYang will ever get over his one-sided love for LinZiang and ever consider him. It can feel like a real bad stomache ache, for real. That is just my impression. Its great he can cover and act like they are a couple but I don't know that he thinks it will go anywhere.