Is it normal that i get a sensual pleasure from the fear of others?

I started watching a couple different anime's in which they both are fairly graphic and dark. After a few episodes of each I started realizing that I was getting aroused from listening to the screams and seeing the fear on the faces of the characters that die. Just to make sure I wasn't imagining it I went to an earlier episode of one of the anime's. I skipped forward to a scene where a little boy was eaten alive right after being tricked into thinking he was going to live and escape. I stopped the video after the scene to notice that I had ejaculated in my boxers from watching it. Is that normal?