@ZombieKiller As you can see from the model responses here, what we are most concerned with, is that you have a good time. It is a kind of, "help us help you" scenario. While, as others have pointed out, you don't
have to tell the model beforehand how long you want the private to be, it can be a good idea to ensure the most enjoyable pacing and experience possible.
I know, if I was the model you chose to share a private with, I would feel terrible if I was unaware of how long you hoped the session would last and I had to leave to attend to prior engagement before you were able to have the full experience you wanted. The goal is to ensure you have a good time. So to best do that, some information is always nice
I feel prior conversation is extra important if there is something specific and crucial to your enjoyment of the private you are wanting the model to do. For example, if you are hoping to see an anal based show and you just take her private without telling her that first, you might be upset (and out some tokens) to discover anal activities are not something she partakes in. This frustrating situation could be easily avoided with a quick chat before taking her private.
Of course, that isn't to say that a private with little to no prior information up front can't be amazing. In fact, I am sure that there are many spur of the moment privates where the stars align and everything falls into place. The right model, the right member, the right time, the right mood - things can go perfectly. But, as we all know from our years on this earth, it isn't always the wisest option just to hope the stars align. Doing that can lead to a lot of disappointment and resentment. Most of the time you gotta nudge those sparkly balls of fire into position to ensure a desirable outcome.
This is your hard earned money! Unless gambling is something you are incredibly into, chat with the girl a bit first and together come up with a rough idea of what the private will look like to ensure that money is well spent