Some people will say that discussion of anything sexual automatically warrants no response but I'm inclined to think that many if not most providers will answer dealbreaker sorts of questions if you gingerly broach the topic.
There are old school ladies who can only answer you in a relaxed conversation on the telephone &other ladies who will under no circumstances answer anything even remotely sexual or having to do with gifts.
Take your cues from the provider herself. If a provider has a buttoned up, reserved presentation there may be a lot less wiggle room than if you're dealing with someone whose websites & ads feature saucy language.
If a girl has a special "PSE" rate that is $200+ her "GFE" rate, naturally that arouses a question of what is included in "PSE" and she's used to fielding those kinds of questions. If a girl has has photographs and a email or phone number...but zero rates..of course she expects you to ask and she will probably answer other questions of a sexual nature.
I'd say you can always just ask respectfully and cover yourself on the backend by apologizing in advance.
I'm pretty relaxed, but when someone gets a little bit too sensitive in conversation I have no problem asking that it be dialed back (and screening especially carefully).
If you think that it could be over-the-top and wind your email/form/PM in the trash can with the provider, try tippy toing around the subject & make references any review that describes what you're looking for (I really enjoyed XXXs review of you, is time with you really like that?)...we're very good at reading between the lines lol.
Good luck!
(Oh and you have an email

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