I've often thought that if it were socially acceptable you could identify an individual female by the look of her vulva just as accurately as any other method.  There's such a tremendous variation in size and shape of the labia majora, even more variation in the labia minora.  Then there's coloration, symmetry, and we haven't even mentioned clit variations.  I'm not sure what you mean by fleshy pussy.  I would think that description would mean large labia majora.  but you seem to be talking about a woman with larger labia minora. In any case, I've never noticed a correlation between a woman's response to oral and the size/shape of her labia.  I tend to focus my attention on her clit, for sure, and make occasional forays to her vaginal opening, with some attention to the territory in between.  Pulling back the clit hood can def allow more direct stimulation, but some women find it too intense and don't like it.  Some require at least a bit of penetration to get off, so try using fingers inside her at the same time you're licking her.  And others simply don't get off from oral, no matter what you do.  I have 2 regular 24yo SBs now.  One is a sexual dynamo, but always prefers to cum by rubbing her clit while I'm fucking her.  The other one cums when I eat her pussy, plus many more times while I'm fucking her.  The variety is wonderful, have fun exploring what your SB enjoys the best!

I'll bet that far too many of the guys she has entertained "down there" never bothered to ask or get feedback. They just assume they have a magic man-tongue and that every woman they lick has immediate earth-shaking orgasms.   That assumption is the difference between the pickup bar-douche she is used to fucking and the mature, sensitive and effective Sugar Daddy she looking for now.  

 
Life is good

 
The Cat

Just ask and tell her that however she wants you to do it is great whatever she wants. Ask again if she is shy. You are down there to please her, so she should get comfortable telling you how best to do it with her. There is a lot of variety with gals; some get so sensitive after they come that they want you to pull away and give her a chance to cool down, while others want you to keep on going for O number two and three. Some want you to suck on it and lick it aggressively, while others want contact to be indirect and only on the hood for the most part.  

From my experience, women with bigger labia and clits tend to want more direct and harder oral simulation while receiving oral, but my experience isn't enough to suggest that it is more than mostly a coincidence. As an exception to the rule, one woman who would completely soak my face when she came is a very petite young lady who is small in body and all parts down there but loved aggressive licking and wanted me to continue it to multiples orgasms. I was rewarded many times over.