Hearts in St. Helena by Grace Conley

When Nick DeLuca convinces his best friend from college, Emme Lawson, to venture out to to St. Helena, California for his-and-hers internships at DeLuca Vineyards and the St. Paws Animal Shelter, he expects the holidays to be smooth sailing.
Instead, Nick finds his crazy Italian family conspiring to work him to death, dress him in a toga on a Holiday Parade float, and marry him off. He needs a little help from his friends right now…especially, a special tough girl who wears steel-toed boots.
Veterinary student and “everyone’s gal pal” Emme is less than thrilled to find herself Wing Girl to her handsome best friend Nick DeLuca in a prank to turn the tables on his meddling family. But the more time she spends as Nick’s “make-believe girlfriend” in Operation Gingerbread Girl, the more she begins to realize that she’s been falling in love with Nick for real for years now. And that deep in her heart, she might not be ready to give Nick up after the holidays pass…