Do most swingers and nudists lose most of the normal sexual cues and turn-ons from being frequently exposed to sex and nudity, so that it becomes mundane?

Er, um, maybe you might want to consider context?

Medical doctors might see a lot of unclothed people, but they (hopefully) don’t get turned on simply by the presence of naked flesh.

Put those same medical doctors in hot and heavy dating situations with people that seductively hint they’d like to get naked with them later on. I’ll let your imagination complete those scenarios.

Also, being a swinger and a nudist aren’t the same thing. Consent to seeing other people naked and being naked yourself isn’t consent to fuck other people besides your committed partner. Besides, nudist organizations usually explicitly forbid any sort of sexual behavior during their events.

What are the “normal” sexual turn-ons? Someone else’s normal might not be yours. That’s probably why swingers and nudists declared those identities in the first place.

The specific heart-stopping and loin-inflaming erotic situation someone has always liked (or has newly discovered) will probably never get boring.