My boyfriend and I have been together for about 3 years (he is almost 41 and I am 29). We have gone to nudist places before as a non-sexual activity, just to relax and we know families from these resorts. Recently, I found under the bed a folder of pictures of very young girls about 12-16. Some were teens from the family we know that were taken on our trips. I have found him very often masturbating to the photos. He doesn't know I know about it. I feel disgusted like I am dating some pervert. He has mentioned to me that all men masturbate to girls this age. Am I out of line by being opposed to this?