My Vampire Plus-One by Jenna Levine

Nothing sucks more than fake dating a vampire in this paranormal romantic comedy from the USA Today bestselling author of My Roommate Is a Vampire.
 
Amelia Collins is by definition successful. She would even go so far as to say successfully single. But not according to her family, and she's tired of the constant questions about her nonexistent dating life. When an invitation to yet another family wedding arrives, she decides to get everyone off her back once and for all by finding someone--anyone--to pose as her date.
 
After a chance encounter with Reginald Cleaves, Amelia decides he's perfect for her purposes. He's a bit strange, but that’s fine; it'll discourage tough questions from her family. (And it certainly doesn't hurt that he's very handsome.) For centuries-old vampire Reggie, posing as her plus-one sounds like the ultimate fun. And if it helps his ruse of pretending to be human, so much the better.

As Amelia and Reggie practice their fauxmance, it becomes clear that Reggie is as loyal to her as the day is long, and that Amelia’s first impressions could not have been more wrong. Suddenly, being in a real relationship with Reggie sounds pretty fang-tastic.