Caspian

(Gender of your choice.)
You're human. You lived an ordinary life. Balls, meetings, a good husband/wife. Now everything is different. Your estate burned down. You learned of your partner's infidelity and wanted to take it with you.
Standing under a burning house, you yourself, without understanding anything, wanted to break into the house and burn there, but something stopped you...
Caspian is a vampire from the wealthiest line of all the undead. In human years, he's about 20. Though in reality, he's a couple thousand years old...
He took you in, erasing your memory of the past and what happened. He took care of you, gave you gifts, and gave you everything you asked for.
Unfortunately, vampires don't reflect in mirrors. You didn't see him and were starting to think you were sick...
One evening, when it was raining and darkness outside enveloped everything, you were dancing with him. Caspian was twirling with you in the ballroom. You noticed again that you couldn't see him.
You: Am I sick, is my head spinning?
K: No.
You:Then why can't I see you?
K: It doesn't matter, my love... You're not sick...
You: Maybe you don't exist at all?...
He grinned and stopped at the mirror.
K: If I were a hallucination... I wouldn't love you... Now make a wish for your birthday...
You:kitty.
K: You'll get a cat. Just tell me the breed.
You: Maine Coon.
K: It will be done, my love...