To be White is to colludein these practices, or to risk censure as "having no sense ofhumor" or being "politically correct." But White practiceis invisible to the monitoring of linguistic disorder. It is notunderstood by Whites as disorder—after all, they are not,literally, "speaking Spanish" (and indeed the phenomenaof public ungrammaticality, orthographical absurdity,and parodic mispronunciations of Spanish are evidencethat they go to some lengths to distance themselves fromsuch an interpretation of their behavior [Hill 1993a]). In-stead, they are simply being "natural": funny, relaxed, col-loquial, authentic.
The same excuses are used even today when being politically correct, being even mildly respectful, and not appreciating racial, sexist and xenophobic jokes means one does not have a sense of humor. The author is being very clear that people participating in these activities often do not want to be categorized as someone who has a linguistic disorder but rather it's categorized as just being "relaxed" and "funny"