they haven't met yet. ever since chu yuechen gets kicked out of her sect, she hasn't been seen again in any chapter.
It was really heart breaking, by the time he met her she was pregnant carrying big stomach and looked at him shocked and starts crying, its somewhere around 1700-1750 chapter. His son was also with her, he looked around 20+, In his childhood he was lost and never returned to his mother. But after he grew up he met his mother who mistook him for yun che. Realizing his mothers sadness and love for his father he couldn't say the truth and fell in love with her. He slept with her resulting in her getting pregnant with her own son So incest tag in the novel is not Yun Che sleeping with his aunt, but Yun Che's own son sleeping with his wife, Chu Yuechan