You'll see all other mortal sinners, the ones who flout the honor owed to gods or guests, or loving parents--you'll see them get the justice they deserve. For Hades holds men mightily to a strict accounting down below the earth; he sees all things, inscribes them within the book of his remembering.
The so-called mother of the child isn't the child's begetter, but only a sort of nursing soil for the new-sown seed. The man, the one on top, is the true parent, while she, a stranger, foster's a stranger's sprout.