The irony of gender roles
Douzi experiences an unfair world that doesn't allow him to enjoy his homosexuality while still retaining his sense of masculinity. In a way, his society says to him, "You can love Shitou, but you must sacrifice your masculinity to do it."
Another layer of this irony is that a closed minded society is pushing a man toward gender dysphoria, which they would no doubt judge him for. The reader gets the sense that if Douzi were to be tricked into some sort of transgenderal identity, that they would judge him for that too, so there really is no escape for Douzi that doesn't involve serious shame.
The irony of Douzi's sexuality
One ironic aspect of Douzi's blooming homosexuality is that he acts out his attraction to Shitou as a living. He plays many female lead roles where he and Shitou act out sexual romances, and the irony is that while they're on stage, it's completely acceptable, but thirty feet to the left, off-stage, their behavior would be considered shameful and evil.
The same culture is willing to accept Douzi as an actor, but not as a real person. This is a terrible irony, and it seems like this would be an extremely meaningful aspect of the novel for performers.
The irony of prostitution
The irony of prostitution is that the women who are exploited typically bear all the shame. They're scapegoats for the desires of the wealthy, and the culture makes it so that a woman like Douzi's mother doesn't really have any other recourse. She's a victim being treated like a criminal just because the real criminals have more social power than she does.
The irony of Communism
Communism is a philosophy created by Karl Marx that explains the rise of the working class and the overthrowing of the 'bourgeoisie' government. His idea was rooted in the equality of man and the injustice of the social caste system that can be found everywhere on the earth. So Chinese Communism should theoretically be about returning social power to the disenfranchised lower classes. Does it do this?
Absolutely not. Chinese Communism is depicted in the novel as the exact opposite. For those disenfranchised lower-class people, the Red Army does nothing but destroy hope, instilling power through fear and shame.
The irony of powerlessness and victimhood
This brings up another irony, the irony around victimhood. It seems intuitive that any victim should be recovered and assisted, by nature of the injustice against them, but ironically (and the book demonstrates this beautifully) the people with the least resources are typically abused the most, and instead of social assistance, they fall to the double-edged sword of abuse and shame, abused by the powerful and then scorned for their state as victims.
