Horror isn’t the only genre - it’s just the loudest one. Or maybe it’s more of an umbrella term.

In horror, love stops being abstract and becomes a material fact. The beloved isn’t an idea anymore, they’re meat. And in making that shift, horror admits something most other stories won’t -love isn’t really about understanding someone. It’s about ingesting them.

Tbh, love hits harder in these genres than it ever does in conventional romance. You said earlier that someone who actually steals your heart would be seen as a villain, not a lover. The villain is the only one brave enough to mean the poetry. A villain has more to offer when it comes to love precisely cuz he isn’t bound by societal shackles. There’s that common line- a hero would sacrifice you to save the world, while a villain would sacrifice the world to save you.

Horror isn’t a perversion of love. It’s more like love without the metaphor. It says that if you truly want to be “inside” someone, you have to be willing to tear through skin, bone, and sanity to get there.

Some other genres that run on the same radical premise -
Sci-fi does it by treating the old romantic wish to “become one” as an engineering problem - characters literally merge nervous systems, upload consciousness into each other’s bodies or become symbiotic organisms. The metaphor stops being a feeling and turns into a technical achievement (or a catastrophe).

Religious mysticism goes even further. The language of union with the divine would sound monstrous if you applied it to a human lover - being consumed, pierced, emptied, eaten, dissolved etc. Some of those texts are more violent than most horror. Think of St. Teresa of Avila describing an angel piercing her heart with a fiery spear, or the Eucharist being the actual flesh and blood of God.

Yeah, I can see it being considered horror if we're treating the genre as an umbrella term for anything that refuses to keep its metaphors safe.

And I’m a little offended you called Hannibal a horror (kidding, don't take it seriously.) It’s a love story. The crime is just the setting!!
“If I saw you every day forever, Will, I would remember this time.”
“I am not fortune’s fool, I am yours.”
“I’ve never known myself better than when I was with you.”
“I don’t know whether either of us can survive separation.”
“You came here to get the old scent - why don’t you just smell yourself?”
“My time - before you and after you.”
Plus Bedelia’s entire monologue about how deeply Hannibal yearns for Will. That’s straight up romantic material. Strip out the murders and Hannibal is basically one of those dark romance books people lose their minds over on BookTok. (Okay, fine - it is a psychological horror thriller. But the point still stands.)
You just don’t get dialogues like that in regular romance.