I'm an amateur photographer that has helped out on a couple of wedding shoots for friends and family. I've been approached by someone looking for a photographer willing to shoot a nude wedding. I have no idea of the venue or whether the wedding will take place indoors or outdoors, but can anyone think of what special considerations, beyond the obvious, need to be given to such an event?
Talk with the fiancees about what they expect to receive as a product. Since you haven't done it before, you aren't being hired given your expertise about it, so make sure to talk with them and see if you can find out what they expect.
Examples: color or b/w photos? Should you take some extra care to not show something in the photos, or you just should take them as if it was a regular wedding with clothes on? Sometimes, in weddings, a special attention is given to the bride ornaments, dress, shoes, whatever. Should a special care be given to the "not clothes" aspect of it or not?
Skin tones in compositions: when there are more skin appearing, different skin tones might prevail over others. A red face might appear much stronger when there is some pale neck and chest around. Add more than 2 persons in the composition and you'll might have trouble setting it all up.
Consider that the post-processing might take more time from you, given points 1 and 2. So you'll have more work, which can cost more. Consider that, or you won't be able to charge more if you need to. And also be nice: if it went smoother than expected, you can give some part of the payment back.
If you have more restrictions (per point 1), make sure to take more pictures, with slightly different compositions, so you can select better RAWs before you begin to post-process.
Light is important, and soft light / colored light might provide a great help, since white flash over skin doesn't help.
I would ask: "Will everyone be nude?" and more importantly: "Will the photographer be expected to be nude also?" Good business usually dictates that the photographer for any event be dressed in a manner similar to the participants. I'm not trying to be funny; it seems like a serious consideration as you will have to deal with equipment and pockets come in handy.
Different color pallete. Weddings are known for high contrast, tux + white gown. Not making people into inkblots or blank paper is top priority. Here, you'll be releived of that but have to get subtle midtones. Get flesh tones right, so calebrate the white balance with a grey cloth and color chart.
BTW I'm experienced with nude glamour photography in a studio setting. That was 15 years ago under classroom conditions, not a modern Digital camera. But my thought is you can treat it as nude and nature shots, irregardless of the activity. Nature shots is catch it when things happen and stay hidden; glamour/art is dozens of takes and fussing over the shot. You won't have the latter, so rehurse! Learn how to light it and how to compose, with a staged version ahead of time.
As an outsider, you're not going to be nude even if they all are. You're a working person who needs to be uniformed so you dont look like a perv. Dress like you would dress unless they ask you otherwise, and even then you're a professional and you're there to respect them and work for them, not be naked. They hired you knowing you're not a nudist.
Get all the normal photos you would get if thats what they want. Keep the photos under lock and key. Do not put them in a cloud. Keep them on a drive, give them the drive, etc.