Although the experience of that night was shocking enough to make Cen Dongsheng's feelings towards An Zhizhen extremely complex, in terms of the outcome, he obediently went to sleep in Sister Zhi Zhen's house that day.
His injuries had not fully recovered. The "Undying Bone" superpower took the young man several hours to revert from a skeleton back to human form and what remained was the time for natural healing.
For Cen Dongsheng, during a fight, as long as the injuries didn't affect high-intensity actions, it was as though he wasn't injured; but during the recovery period, he needed to eat and sleep a lot to heal. This was the experience he had gained from past battles.
Therefore, even though he knew he was sleeping under the same roof as a mature and beautiful elder sister, he was still able to sleep soundly without any psychological barriers as soon as his head hit the pillow.