I would cease all contact.

I would be worried about how the photo's are being used. This man clearly isn't together for whatever reason and whilst he might have talent, there are those who have that but are professional enough to maintain the confidentiality of their clients. What are his credentials? If he has a webpage, surely there should be a few sample photos (with the permission of the sitters) then a link for requests/viewing of portfolio's to be done face to face? You maintain he isn't a 'creeper' but lost photos of a sexual nature that were taken for free? Sounds creepy to me...

You're a smart person with a strong sense of self, no one here needs to tell you to be careful when it comes to the BDSM community -- i would however encourage you to go with your gut instincts on this one. If it seems dodgy then it probably is.