In reality, Jian Kang Lu was right. Part of it was only his illusion. The real scene was a bit different from what he imagined.
At first, Bai Yutang just dazed the whole day, thinking about Mu Xiaoya's advice to him. Return all the physical conduct Jian Kang Lu did to him previously.
Mu Xiaoya logic is : Jian Kang Lu touches him —> He doesn't mind —> He likes Jian Kang Lu.
So, if Bai Yutang does the same, and Jian Kang Lu doesn't mind, then Jian Kang Lu likes him too. Mu Xiaoya even screamed and grabbed his hand tight when she told that line for the fourth time, because Bai Yutang still resisted her idea.
Bai Yutang is afraid. What if he did that and then Jian Kang Lu disgusted with him? How if Jian Kang Lu threw him away, and said that he despised him, for a man like Bai Yutang just took advantage of his kindness. What a filthy person.