I love horror in porn games, but like actual horror. Even better when the horror is the main focus and then you have non-sexual nudity or risqué clothes. It makes my bran tingle.
There are some OK to pretty good horror porn games. I've never understood the FNaF thing. The games usually aren't that sexy but it's like you're watching a train wreck in slow motion and you want to see how far the rabbit hole goes weird.
I don't normally take horror with my horny, but I don't as a rule think they should be separated as long as the themes make sense.
What I really don't like is horror where the porn content is entirely locked to game-overs or getting 'caught' by the enemy. Then it isn't horror any more since the point isn't to scare me with the antagonist, but to make me seek them out to get fucked.
This is especially weird when I find myself trying to avoid enemies and monsters not because they are scary or dangerous, but because I've already seen all their scenes and want to find new stuff.
I have never played any good horror porn game (or many for that matter) to have a good opinion on this, but I am of the idea that any genre can have something that I will like, some just harder than others
Dark fantasy yes, horror rather no. For me as a non-immersive player, horror usually just doesn't work, meaning horror games fail to invoke any sort of fear in me. I'm still interested in stories about vampires, werewolves, Frankenstein monsters and other creatures usually associated with the horror genre.