Kunti lies about the women not being able to have sex with more than 3 people because she does exactly that immediately before and she knows she did it four times. Does any of the other characters do something similar? Also, this was completely avoidable by getting Madri to do it. Is there any other character who does this?
Kunti warned, The wise do not sanction a fourth child even in case of emergency. The woman who has intercourse with four different men is called a prostitute, and with a fifth she is called a harlot. Therefore, O great King, because you are learned in the scriptures, please do not ask me again to bear children.
"Kunti said,
'You are Kunti’s son, and not Radha’s. Nor is Adhiratha your father. You, O Karna, art not born in the Suta order. Believe what I say. You were brought forth by me while a maiden. I held you first in my womb. O son, you were born in the palace of Kuntiraja. O Karna, that divine Surya who blazes forth in light and makes everything visible, O foremost of all wielders of weapons, begat you upon me.