I'd really like a provider to "make" me lick her ass until I've done it well enough to "earn" the right to eat her pussy. Is this a reasonable request? If so, any suggestions on how to frame this request? I have at least references references I'm comfortable with, so lacking any feedback I may ask them, but don't want to otherwise risk those relationships.

I LOVE to have my ass licked and I can make you go until you have earned the pussy baby, No problem at all! You would be surprised at how many ladies really do like their asses licked
Not unreasonable at all to me
Hugs and kisses
TL

Around here, a fetish would have to be a lot more extreme than that to be categorized as odd.  I'll bet the majority of ladies would be fine with that one, especially since you're not asking for reciprocation on the rimming.

I am glad to see this discussed.  I love rimming a fine ass and would love to find a provider that enjoyed it.  Good to know there are some out there.   One has come forward publicly (thank you Terri Lynn).  Would love to hear from others, privately if you like.