What is the reaction in the room to Linda's revelation that she is John's mother in Brave New World?

When Linda enters the Central Hatchery, the workers are
disgusted by her appearance. She is, to put it bluntly, fat and old. In Huxley's London,
no one ever ages or gains weight, so the sight of her body is something no one can
really understand. The scene only causes more humiliation and derision when John calls
the Director "father". For those in the World State, this word is something to mock; no
one has a father.

In contrast to the hilarity that erupts
at John's words, Linda's accusation that the Director "made [her] have a baby" and that
she is indeed John's mother cause a shocked silence. To the
workers, what she said was the most obscene thing they could possibly
comprehend. Fathers are a humorous if vulgar idea, but
mothers are pornography in this society.