rom my limited experience with COF, most providers, women don't like it.
If you ask nicely, they will either say no, or require limitations. rarely a full facial like in the porn scenes.
1) Cum on mouth only.
Often times they will keep the rest of their head out of the way, or above your dickhead if they
were kneeling below. And often grab your dick to try to put it just on their mouth or chin.
2) Below the eyes.
Same thing, grab your dick while you're coming. Once I tried to grab it back, and it became a struggle over my dick. Since then, I've tried to be more sensitive to their answer to the question "can i COF" since even though I never get to do a full pornstar facial. (i've only been able to do it with permission once in my life)
3) Worst case: blocking during orgasm.
If you are cumming too close to her eyes, not letting her grab your dick, or she doesn't move her head away, then she may just use her hand to block your cum. Then you know she's pissed off enough at the client to do that while you're coming.
Probably bad communication about the question I realize. But another thing could be $. Less than $500, a provider may have more control of the client-provider relationship in order to get the client to compromise for halfway mouth-only lame facials (might as well just be CIM with an inch or two outside the mouth) as opposed to the full ones dreamt about from porn scenes