To answer, I must admit to the world: I am a carnivore.
That's right, people! I eat meat. Bacon, beef, pork, chicken, turkey -- I shamelessly and without guilt consume them all, and enjoy it.
I am not the only one, on this planet, there are both male and female carnivores, and somehow, we fall in love. I have been so afflicted more than once.
Vampires can be like anybody else, it should not surprise us if they view their victims as prey and food animals, and reserve their true regard for their peers: Other vampires. Nor should it surprise us if one vampire falls in love with another vampire; even if in your world vampires cannot have children.
Romance and love does not have to be about having children. Ask any homosexual married couple. Ask any woman that marries after menopause, or marries after hysterectomy or other disease or surgery that prevents her from having children.
Vampires are a certain kind of predator for food, as are most humans, and that is all you have to use from the clichés about them; discard anything you think about vampires that would prevent them from falling in love with each other. Like many authors before you, write about your vampires, not somebody else's.