Russian?

I have read a few posts on GFE vs PSE, but nothing that seems to go into specifics. Is Russian generally assumed to be okay if a provider offers GFE? "Naughty" GFE? Exclusively PSE? Based on nothing other than my own speculation, it seems like that might fall in a middle ground between the two.

And -- whether or not it should be assumed to be on the menu...when is the proper time to discuss something like that? I guess this is a more general question -- at what point in the interaction is it okay to specify exactly what you're interested in? Before meeting in person? Once a session is underway? How and when do you communicate any specific requests so that your provider isn't caught off guard or put in a position where they may not be comfortable with a request?

but sometime they want you to do it in reverse or even at a 90 degree angle to that you don't cum on their face.

After the envelope has been tendered is the time to start getting into specifics.

The terms pse and gfe and two of the most overused & misused terms in the hobby. Everything you prefer in a session can usually be found by reading the juicy details of the reviews. If you're not a VIP, you need to be, so you can access the juicy details section.  You should see the things you like, over and over in the juicy parts of the review.  In all my years of hobbying, I have never asked about sex acts before a date. Have I asked during a date, sure.  I read reviews and know what to expect. Have I ever been surprised ? Yes, basically the entire hobby is a ymmv situation. Have I gotten a cbj when every other review said bbj, yes.  Have I been invited to Greece, when no other review mentioned it, yes. When I contact a provider, either by email or phone, normally, I'm ready to book so it's day and time I'd like to see her, and of course giving her references so she can screen me. Have you read the "self help center" yet. If not, it's in the upper right corner near the life preserver. It's well worth your time. Good luck and write a review on whoever you decide to see.

You must do your research.  Read her ads, read her web site, read her reviews.  Yes, you need VIP.  VIP costs less than a spoiled date or wasted opportunity.   In the end, it depends what you and she agree to do when you are in private.  Once you are both naked you might whisper say...  "Can I CIM?" or "Can I Cum on breasts?"
skb

GFE and PSE are meant to describe a feeling or impression more than a particular set of services.

I don't often notice Russian mentioned in reviews, but I don't think that's because providers are unwilling to do it. If I wanted to line up someone for it, I would look for reviews that describe a girl as accommodating or open to requests. And big tits would probably help.

You can ask once a session is underway, but not before.

I agree you can ask while underway. It does not require any preparing for and most ladies I have seen will ask what you like once you get started. The only caution I have found is that some ladies with implants will not offer this if it is painful to push her breasts together. I have run into this already myself.

After you've been going at it for a while and you haven't been able to cum (or maybe you're holding back), tell her that that gets you off. Providers want you to cum, the sooner the better. I've never had one say no to that request. GFE, small tits, doesn't matter. Just don't be surprised if they shield their face with their hand.