What I Thought Was True by Huntley Fitzpatrick

From the author of My Life Next Door comes a swoony summertime romance full of expectation and regret, humor and hard questions.
Gwen Castle's Biggest Mistake Ever, Cassidy Somers, is slumming it as a yard boy on her Nantucket-esque island this summer. He's a rich kid from across the bridge in Stony Bay, and she hails from a family of fishermen and housecleaners who keep the island's summer people happy. Gwen worries a life of cleaning houses will be her fate too, but just when it looks like she'll never escape her past—or the island—Gwen's dad gives her some shocking advice. Sparks fly and secret histories unspool as Gwen spends a gorgeous, restless summer struggling to resolve what she thought was true—about the place she lives, the people she loves, and even herself—with what really is.

A magnetic, push-me-pull-me romance with depth, this is for fans of Sarah Dessen, Jenny Han, and Deb Caletti.