Does anyone know whether, in places where prostitution is legal, refusing to have sex with a customer on the basis of race, disability, etc. violates anti-discrimination laws? Someone who feels distaste toward, say, one-armed white males probably can handle mixing them drinks, showing them houses or even performing their enemas, but I wonder if we would make such a person liable under civil rights legislation for refusing the business of a one-armed white man who wants to have sex with him or her. A 2002 article from UChicago's Ethics journal touches upon nondiscrimination, but only as one of many regulations that would fall upon legalized prostitution and detract from workers' sexual autonomy. The author's footnote mention of rural Nevada brothels fails to say whether any have run afoul of the kind of laws he perceives as interfering with specifically sexual autonomy.
This could be an issue for non-prostitute sex workers; if a workplace countenances a stripper who refuses to do lapdances for black customers, would those customers have a basis on which to sue the club, as long as it had admitted them in the first place? Sex-oriented public accomodations certainly lack the element of necessity that undergirded the Civil Rights Act of 1964; Congress could claim that the interstate commerce clause gave authority to forbid discrimination, because if a person of color traveling on business could find neither a roof over her head nor a place to eat, this incapacitated her from business travel and ultimately impacted interstate commerce. Assuming that there was some commercial necessity for patronizing a strip club -- taking clients there, perhaps -- as long as the black businessman is admitted, he can engage in client relations. Being refused the lapdance might be embarrassing, but the commerce clause isn't there to save people's feelings.
This bears certain parallels to the German unemployment compensation scheme that, because brothels had been legalized, might have required unemployed people who had been offered jobs by brothels, phone sex lines and other parts of the sex industry to accept them or lose benefits. In both cases, sexual autonomy has a price: that of a lawsuit and attendant monetary penalties, or of lost benefits. But in neither case can someone be literally forced by government coercion to have sex if he doesn't want to.