What to do? My fiance took pictures of younger women's butts on our vacation together?

I confronted him about it and he said those women were "just in the way" when he took those pictures. I said he needed to see a male therapist about his fetish with his picture taking. He deflected my question about seeing a male therapist. I still get the shakes when I think about what he did and get a sick feeling in the pit of my stomach. Am I being uptight up this. I'm not a prude by any means. He is in his 50's.