In which episode is Wei Zi quarreling with Er Kang?

In the ninth episode of the second part, Emperor Qianlong repeatedly hinted at the marriage crisis of Erkang, Wei Zi, Yongqi and Xiaoyan. At this time, Wei Zi, threatened by Sang Ni, finally turned her doubts into tears and collapsed. Wei Zi and Er Kang also had a serious misunderstanding in a chaos, and their vows of eternal love also caused ripples.