Princess Zhu Huan, which episode is the quarrel between Li Erkang and Wei Zi?

In the ninth episode, Wei Zi of Qing Er mistakenly thought that Erkang and Qing Er had a past and refused to listen to Erkang's explanation. She also said: If Erkang's life was so serious, Erkang walked out of Shu Fangzhai with a blue face and never looked back. Finally, Wei Zi was caught by Galeries Lafayette and the Empress Dowager and taken to Cining Palace to sober up.

It pains Erkang to realize that it is too late for him to make a mistake ... (I typed this word for word)