I don't read hentai. I've looked at it a few times and found it hilarious (there was this one called "Super Taboo" where a boy would keep getting possessed and fucking his mother and sister...that one was expecially funny), but I think anyone reading this shit and getting aroused is fucked in the head. Still, if that's your thing, you should be allowed to do it. I don't see how it hurts anybody.