Why does Gerald perhaps not change his ways and go against the class system?
How people see Gerald is of utmost importance to him. He is prepared to help Eva, but maintains an image of an honest and respectable upper class man- he can't be seen having an affair.
He must uphold that respectability because of his family business and to fulfil his father's expectations of him.
Hence, even if he disagrees with the class system, he must still believe it.
Although, he does seem to recognise his flaws- which both the Birling parents can't.
