Facing the veiled invitation from Xiankong Ancestor, Shi Feiyang didn't even think before immediately rejecting it in his heart.
Even Geng Peng, for one thing, he envied the Twelve Heavenly Forbidden Technique, and for another, Geng Peng had protected him in every way, eventually sustaining serious injuries to save his life and bring him to Wuding Island as he neared death. Only then did Shi Feiyang call him 'master' before passing.
If it weren't for the fact that the Heavenly Book could never be taken out of the Jade Box, if it weren't for his desire to learn the "Chi You Three Disks Scripture," he wouldn't even want to seek out Geng Kun.
Indeed, Xiankong Ancestor's current power was something he could only look up to, but as to becoming his disciple, he was unwilling, let alone becoming his grandson.