I'm not a very active hobbyist, maybe once a month at most, and it can be awkward establishing a rapport with a provider on the first visit.
Hopefully, when a provider does her homework screening me, she'll find this thread and get a better understanding of what I like.
Truth be told, I've met a couple of ladies who I was GLAD they didn't sit on my face... It's personal thing, and trust has to go both ways... Cuz STDs will too!
Fact is, most of the ladies here are gettin' it far more often than I am, which is fine, but I want that pussy to taste like pussy... Not like Nonoxynol-9... OR worse!
FWIW, I usually bring a small bottle of Listerine with me to clean up right after. I'm D&DF, and plan to stay that way.
Another variation is panty sitting or panty-hose sitting. That way there's no exchange of fluids, but there's still the bump-n-grind...