Not Overdoing Politically Incorrect Villiany

So two of the villians (they're siblings) initially appear to be (somewhat Jerkass y) Noble Bigots who help out the main characters, but then return as Knight of Cerebus as helping the Big Bad. One of them stops when things are escalated a little too far but the other proceeds to cross the Moral Event Horizon while trying to get revenge on one of the heroes. They both happen to be Evil Aristocrat who never needed to work for a living, weren't raised to have too much of a work ethic, and are quite acoustomed to their Upper-class bubble.

• I don't want too over do it too much, because then it would get fucking ridulous. But the fact that one of them believes in No Bisexuals is actually a plot point.

I'd just appreciate any input you have and any specific cliches that I should avoid.

It would be helpful if we could read an excerpt. Because, you know, it's really all in the execution.

I'm still in the process of outlining, but I just wanted to know if there's any specific pitfalls I should avoid to avoid being too Anvilicious or such.

I am working with a Politically Incorrect Villain too. She's an Indian pirate queen who calls the African heroine a "black bitch" during the climactic battle, and obviously this gives the heroine all the more motivation to cut her up into pieces. Personally I think it's an awesome concept, but I have definitely encountered the attitude that racial insults are taboo in literature. Haters gonna hate, I guess.

Racial insults are absolutely not taboo, especially if your work is something vaguely resembling a period piece (obvious Indian Pirate Queen disqualifies it as a straight attempt at such).

One thing that is important to remember is that Class Warfare as a part of culture is a relatively modern idea. The classism of older times was more subtle precisely because it was usually unchallenged. If your work is set in one of those points of challenge, realistic classism can be easily established through a sort of bemused indignation that things are not as they should be.