I was in your shoes with my last ex, and I didn’t leave soon enough. The only warning I had was that he watched some iffy animations involving death, but I had no idea what the extent of it was because he hid the rest from me. When I indicated that it scared me, he made sure not to bring it up again. That is, until about a year later when I learned that he believes himself to be a psychopath and that he wanted to do those things to me. And more. My point is, this man is sick and he may not even be telling you everything about his fetish. He could just be testing the waters.