To be fair, even though this might be a troll post, I myself have often wondered how guys do DATY on ladies at the spa for the same reason. When i hear the girls tell me stories of how the guys like to lick there pussies because (and this is the girls idea of why not mine) these men feel inadequate sexually so they try to "pleasure" the female sex worker thereby feeling more confident in themselves sexually. I'm not sure if this is true for all men who preform DATY on women at the spa, this is just the perspective of a few MPA's that i know personally.
Anyway, back to the nutting first thing, it really does happen, then that girl gets DATY from other men during the day. Perhaps when the girl goes pee the last of the cum will be gone, and if she showers your good? Perhaps not. Either way, pretty fucked up. Also, now that i think about it...i don't like the idea of my cum in another mans mouth either...damn, really fucked up.