Comment by PockyChu on A Master, Who Woke up as a Concubine - Chapter 43

@PockyChu   you know the person pretending to be the emperor that's the boy who got her pregnant it's mentioned in the past chapters

@Flynn I guess that lady On was impregnated by somebody else since the fake king is impotent and that is why he sleeps around with the concubines. It was mentioned when the king and his head eunuch were discussing how lady On got pregnant since the fake king is impotent.

@PockyChu As i talk about Emperor didnt want to sire any child yet, so they confirm body-double is indeed Sterile.
But ofc Lady On which considered 2nd person from their House, cheating by concieve child from other man to fake as if it is the 1st potential Prince of this era to gain influent in the court.