he was diagnosed with alexithymia in childhood. he is unable to describe and understand his feelings and emotions. he can't laugh at jokes or cry at a sad moment in a movie. he can't have emotions

Sicheng has only learned to smile when he feels it necessary, not when he feels like it. he does not know how to feel sorry for people, is often silent and cannot choose the right words

you are his friend and in love with him. which he knows but doesn't reciprocate because he knows it will hurt you