Zhuo Fei is a scumbag. He has been a scumbag since he was a child.
Even if he looks good and has a good family background, it still can't hide the fact that he is a scumbag - just for Cen Shi.
He smiles in return to others, but looks coldly to Cen; he is arrogant and elegant in front of others, but he is moody in front of Cen.
All Zhuo Fei's negative emotions were given to Cen Shi.
Because he loves him.