| Quote #1
Honey: I didn't know until just a minute ago that you had a son.
Martha has committed a cardinal sin by mentioning her and George's imaginary son to other person. It's this action that eventually causes George to destroy the illusion of the child forever.
| Quote #2
George: the one thing in this whole sinking world that I am sure of is my […] chromosomological partnership in the…creation of our…blond-eyed, blue-haired…son. (1.649)
It's pretty ironic that the one thing George believes is not an allusion is the creation of his son. Of course, we learn by the end of the play that their son is completely fabricated.
| Quote #3
George: national boundaries, the level of the ocean, political allegiances, practical morality…none of these would I stake my stick on anymore (1.649)
This statement points out that even things that seem so finite to masses of people are really just agreed upon illusions.