Minnesota
Elan; Just reading your thread made me instantly hard. 
..... you might mess up her checkbook--was it a fancy one? 
And no, I've never had any provider complain about that. In fact, one time a provider took a pic of the aftermath with her phonecam (from neck down on me) 'cause she thought it was pretty hot.
I would say be more careful whom you're using as a splat mat and perhaps ask her where she wants you to cum next time you go out because that can really scare a lady, it is a safety issue for many .
Don't take me wrong, I am no way afraid of cum at all.
I think it's kinda hot if a guy asks where I'd like it though.
She was mildly upset about it and made some comment about how she was going to be nice and not charge extra.
I've done this before with several other providers and nobody else seemed surprised. Am I in the wrong here? What is he etiquette on this?
BTW I paid her $220 for an hour and got shooed out the door after about 40 minutes which is the MOST I've ever paid.
I tried to find an animated GIF to describe what I would do in the heat of the moment but I couldn't!
It's still hot IMO.
I think sometimes guys are a little hesitant to ask "where do you want it" because the answer may very well be "I don't" and that's kind of a buzzkill. I will say that over my many years of hobbying, something that I have been asked very rarely--maybe 2-3 times ever--is her asking me "where do you want it?" If you want to put limits on that you can actually do that by how you ask. "I want it on me, where do you want that to be?" at once makes your guy's knees tremble, while sending the subtle message that CIM, for instance, isn't what you are asking for.
Some women love it, some are neutral, some would rather not but will tolerate it, usually followed by a mad dash for the bathroom. I'd be more inclined to ask "where would you like it?" if I knew in advance that it was actually liked.
Should I phrase that as 'Gliding Lessons' or 'Gliding Tours'? Because I don't think it would make sense to ask if you speak glider . 
Um, for me, I don't need lessons, so it'd be Gliding Tours
...for me, at least. It kinda reminds me of dry humping back in my Junior High School days. If ladies are going to constantly entice me with photos of their beautiful butts, I'm going to use any means I can think of to enjoy this delicious part of a woman's anatomy.