I remember it was the chapter where he met his lover from his previous life and she got pissed when he started talking about sex
I have not read it in a while, so I am not on par with the novel. I can't remember this scene, I may believe, however, that you might also remember some details wrong, as the Mo girl was just a child. There is, however, something you are reminding me of. The "Yin body" (can't remember names) girl might be who you are referring to. They were not in a relationship in the past life, but there were some one-sided feelings from her in the Lower World in this life. She gets pissed because he believes the reason she is still a virgin is because the "prince" has too much yin energy in his body (reason for why he practices cultivation arts for women) and can't get it up in bed. He thinks she's there to search for a miracle drug to produce an heir. I believe. It's been a while, so this everything I remember. I can only tell you that it's part of the "doctors contest" arc or something similar.