Is my boyfriend mentally unstable?

He likes to watch films like American Psycho, Saw, deep psychological horror or thriller films, and he just finds them more interesting to watch than Comedies and Romantic films. I'm a girl, so naturally, I'd prefer films with less violence. I hope he isn't that into blood and gore... My friend is scared of him but she barely knows him haha He is also very intellectual, he thinks before he answer questions, he's brilliant academically, and he's quite a normal guy. He just like to look into people's minds and doesn't give anything away about himself. We're good friends, but there's something about him I still can't quite grasps, eg his choice of music, films, opinions on certain things... We haven't been together for long. He's a really lovely, thoughtful person. Thanks! :)