It does depend on the photographer of course. Certainly you can't go to a Sears Portrait Studio and ask to do Playboy style shots. After turning red they would politely ask you to leave and threaten you with security if you didn't.
But aside from the standard policies of retail photographers, professional photographers operate more on the basis of personal limits. Some photographers won't shoot nudes or Playboy style images (or beyond for that matter), some will. If they don't have a formally stated policy on their website, you'll have to judge from the content of their portfolios whether to even ask.
At INFINI Boudoir, it is our position that it is inappropriate to suggest a certain level of nudity to our clients. On the contrary, each client has their own comfort level and for a positive photoshoot experience, the client needs to be the person that sets the tone for the shoot. We have found as well that a client's comfort level may change during the course of the shoot and they may decide to do more risque shots. In order that we meet our client's expectations, we always ask what their modesty level is.
Some thoughts to consider for your own shoot:
Getting What You Want
You don't do a boudoir photoshoot every day, and it doesn't come cheap, so you should walk away with the shots you want. If you want super sexy shots, you should say so. Remember, it is inappropriate and borderline unethical for a photographer to suggest shots of this type to a client, so it is up to you to indicate if you want them.
You Are Not Committed
You can change your mind either way, even at the photoshoot.
At INFINI Boudoir, we strive to capture the client's vision whether they want to shoot in a shirt and jeans, nothing at all, or anything in between. And we always apply our artistic brand of photography to the process.