do people with fetishes usually have more then one?

My boyfriend and I have been in a relationship almost 2 years about a year in our sex life started to dwindle and out of insecurity I went snooping through his phone. I didnt find another woman but I found some interesting videos. I learned he was into Vore the fantasy of being a tiny man and being swallowed. I almost let it slide because I didnt know how to confront it but weeks went by and everyday he was on his youtube channel (public to the world) downloading vore videos while I was completely sexually frustrated because he had no interest in me. I finally confronted him after I couldnt take it anymore and I had to ask what the deal was. He was embarrassed but I explained to him that I was completely freaked out and offered to let him look inside my mouth, even got gummybears to eat for him...while he wactched me play with them of course. This seemed to help for awhile and then bam all the sudden no interest in me again.... and at that time I found new websites he was visiting regularly one universaltgp.com was very alarming... the girls looked 12 to me. There was several similar sites which claimed to be thumb galleries but really only lead me to more risque sites at each click. I confronted him about this and he assured me they were all 18. But they dont look 18. And the appeal of a 12-14 yr old to me is sickening. I could get over a vore fetish because the fantasy is humanly impossible but the idea of him being attracted to girls who have barely reached puberty...that scares me. He grew up in foster care and has told me his childhood was awful but never elaborated on why and now I am seriously questioning if these fetishes have something to do with early childhood sexual abuse. I love this man and we are both at an age where marriage would be our next step, but I fear that the ladder of his fantasies might be one he wants to make a reality..... Can anyone give me real advice on this?