The answer isn't really that complicated when you put it in perspective ...
Ophelia, I sense that you are actually wanting some input here .. . since your usual hysterical banter is glaringly absent. ... So, for what its worth, here is my 2¢.
There is no reason whatsoever to bring up the issue of how you make a living until such time as you both are considering entering into intimate activities. That is the appropriate time to discuss sexual history and safe sex practices. There is no reason to divulge such intimate personal information before that.
Honestly, I think there are many other things I would query first: politics, for example. I jump to the tough stuff very early - especially the highly controversial issues about which I feel strongly and passionately hold as a personal values. In this case, I would suggest garnering his opiniion on freedom of choice and a woman's right to unilateral and unencumbered decision making around her body. Not only will this give information on what his views are on something that I consider a self-defining personal standard, but it will demonstrate his skill at discussing things, how he handles debate and/or disagreement, etc. In addition, with this topic, I will get some idea how he feels about human rights and women's rights in particular. If he believes that the government has the right to a voice in how I may use my body, then I already have some idea where he stands on prostitution. This or any number of other highly held beliefs will usually help clear the wheat from the chaff anyway; he may be selected out of your consideration at this point, and the rest of the discussion is moot.
There is a vast wealth of infomation in a conversation like this about his personality, charachter, manner, value system, priorities, attitudes, interactional style, etc. that will help you make an informed decision about your willingness to get intimate at all. Is he intolerant and judgmental? Aggressive, abusive, compassionate, caring? Does he listen well (or at all)? How adjusted is he? Is he controlling? I expect he will have baggage, but just how much, and does he expect me to carry it?
Second, I would question his tastes with respect to sex and sexuality. Is he open or uptight? Do you and he he find the same kinds of activities interesting? For me, there are plenty of men with whom I wouldn't think of getting into a relationship because their sexual tastes are not compatible with mine. They are not interested or open, they are fixated on a particular fetish that doesn't fascinate me, etc. Or they have no imagination at all. They are not interested in exploration, growth, spirituality, etc.
I would suggest you sit down and go over your own personal values - I can send you a values inventory to help you with this if you would like - before you meet with him again. Try and isolate what is most important for you and what you need to see i(versus what you would like to see, and what you really don't care about) in a potential partner. I would then prioritize the list and devise questions or activities you can do together to give input on these qualities or characteristics.
Third, I would try and get an idea of what he thinks he wants and is looking for. Then ask the important questions - is he in a relationship? Is it serious? Has he made commitments in that relationship that are being violated by his spending time with you? Do his goals jibe with your own? How about his attitude and approach to his partner or ex-partners? This speaks more about a man than anything else, I think. If he is currently treating his woman badly, or he speaks badly of his past relationships, I would probe further.
When you come to a point that you decide you might want to enter into a deeper relationship, then, and only then, should you broach the subject of sexual history. Quite honestly, if he has more concerns about whether you were paid for your time than your health in the matter, you should run fast anyway.
In the meantime, tell him you work independently as a consultant. Your areas of expertise are your own - call it whatever you want - intimate communications, leisure management consultant, sensation training. Try not to get too definite if you can -- just ask a question about him, and I'm sure he'll forget you didn't give a complete answer. DO NOT LIE - just don't offer more information than is necessary.
Consider yourself the border guard here. You are interviewing him to determine if you want to give him access to your territories. You already have a pretty good idea of your personal value and worth; his response should neither validate nor invalidate what you already know of yourself - that is your own divinity. Instead, consider carefully what you require and expect from someone to whom you are offering yourself, time, skills, and expertise "for free".
The question isn't really about what he will think of you, but what you will think of him when he responds badly or well.
Good luck.