Talking to a former fine Thai favorite of years back, I reminded her that when she first started dancing she would DFK which I enjoyed. Eventually she stopped and along with becoming mechanical I stopped spending much money on her.
When I mentioned she stopped DFK she said "well, you never asked for it".
I've always hesitated to ask for worry of repulsing the honey at the thought of kissing my fugly PL ass but I have met a rare few that will initiate kissing and seem to stomach it pretty well. I tipped them all generalosy.
Kind of funny how I find it easier to ask for a bj than dfk but it is.
And yes, nasty hygene, she just blew someone blah blah...I don't give a shit.
In the P4P asking for whatever is not obscene, most of the providers have heard and seen it all, so if DFK is something you really want, then just ask for it, no need to be embarassed.
That being said, for me the DFK experience is much more enjoyable when it feels natural and not routine, which by asking (and paying for) might seem to diminish the experience, though once engaged in a DFK session all the blood heads south and who cares what I thought, just enjoy the ride.