many are tentative at first and then respond if the oral is to their liking
some absolutely love it and when offered jump at the chance
a few are dead set against it, worried about fluid exchange? revolted by it? bad previous experience? hard to say
the Chinese girls tell me that Chinese men will never do this, after a session where they have gone from tentative to, maybe this is ok to, don't stop, don't stop....... I get asked to make sure I come back again. Never sure if this is genuine or that they look forward to what KK used to call BFE (boyfriend experience). I usually find out in a next session (if there is a next session) that it is genuine by the session if it goes overtime, offered something to eat, drink. Offered some of the up-sell extras in the session without any additional costs. In other words begin to treat each other as lovers.
Happens sometimes and adds greatly to the overall experience. Mostly with the MILFs only once had this with one of the younger ones. One used to nickname me "the husband".
Probably a simple concept, offering to genially pleasure someone normally is greeted with positive response. Many women can't or don't achieve orgasm from intercourse or intercourse without sufficient foreplay. I suspect that this profession can leave them very horny and very frustrated in terms of needing release at some point. For someone who can take them there you can probably expect appreciation in the form of warmer service and interaction.
No doubt many here have experienced the same thing.