I'm a huge fan of Nabokov's and have read Lolita several times... But I've never heard it described as horror before and you are so right! I guess before I'd have classified it as tragedy but horror fits so much better.

It's basically a horror story told from the point of view of the monster.

The only "tragic love story" is maybe Dolores' mother trying to warn the world about Humbert being a pedophile only to be hit by a car and killed, unable to save her daughter. Or maybe Dolores' tragic battle to love herself and escape from all the men who want to take advantage of her.

Rowling with another steaming hot garbage pile of an opinion on sexual abuse, no surprise there. What an awful person.