Shu Yu sipped her tea calmly, "Anyway, the Second Prince and Gong Qiu are indeed related by blood."
Meng Yunzheng gently tapped his fingertips on the tabletop, "You're right, whether he is or isn't, we can claim he is. But we can't get involved in this matter ourselves; we need the Third Prince to stumble upon it and lead him to think in that direction."
Shu Yu gave a thumbs up, Smart.
Although the plot of the story states that the male and female leads uncover their illicit affair, she had already verified that the process could be changed—as long as the outcome remained the same.
By replacing the male and female leads with the Third Prince, the thorn in the Emperor's heart would then be this son, and the Fifth Prince could instead extricate himself.
But still...