Chen Fan was not afraid of the Loong family going back on their word.
The difference between humans and beasts were a sense of dignity and respect. The loong family had been jumping up and down, challenging him because they didn't quite understand his power. However, after seeing Chen Fan's ability first hand, and knowing that whatever they did would not affect Chen Fan, they would behave obediently like Chen Fan's lap dog.
However, Kunloon was a different story.
Kunloon was one of the four deadliest Gong Tau masters, a Perfected Cultivator at the peak of the Dharma Cultivation. He was even slightly more powerful than Chen Fan when he was still in the early-stage of Ethereal Enlightenment level. Such a mighty figure might have treated Chen Fan with respect now after he had recovered and regained his Pupil Art, he would seek to harm Chen Fan again.
