Not His Vampire by Annie Nicholas

Magic is real. Shifters exist. Trixie Russell know this. Everyone does. But no one told her about the monster lurking in the basement of the dragon’s castle. Not until it was too late.
Victor Petrov is ancient, and vampires his age should not lose control of their hunger. And yet, thanks to the dragon who chained him in a dungeon to protect the citizens of New Port, that’s exactly his problem. Then in walks a human female with cotton candy hair who smells like sunshine incarnate, her pulse a melody in his parched ears, and the fragile thread of his control snaps.
Like it or not, Trixie is now tied to Viktor’s, and he seems short a few marbles. She plans on making his eternity a misery until he reveals they have an enemy in common. Trixie is totally on board with helping him escape so she could get her revenge. After that, she’s done. They’re over. She wouldn’t be his vampire.