The Guy Next Door Billionaire by Heather Horrocks

A man who no longer trusts love! A woman who has always loved him!
Popular action movie star and billionaire Noah Sullivan wants to help rebuild Coconut Island after a hurricane by putting on a movie-related conference. He brings his boxer dog because he hasn’t let a woman into his life since his bitter divorce two years before. When his business partner brings his sister along—the same redhead Noah thought was cute when he was ten and she was seven—he’s blown away by the difference twenty years can make. At twenty-seven, she’s a knockout, even if her teeny-yet-feisty Chihuahua is ridiculous. How can he romance the girl who got away when everything he says or does ends up on the cover of a tabloid?
Talented photographer Emma Archer agrees to help her brother with a huge fundraiser and figures she can avoid her childhood arch-nemesis during the week of the conference. That proves impossible as they’re staying in the same house and she’s drawn to his warm, funny personality—just like thirty million other women on the planet.
What do fire ants, barking dogs, a haunted house, and bonfires on the beach have in common? They’re all throwing these two together. Can a teenage crush turn into a happily ever after? Or are they too damaged to have more than an island romance that ends when they fly home?