People We Meet on Vacation by Emily Henry

Poppy and Alex. Alex and Poppy. They have nothing in common. She’s a wild child; he wears khakis. She has insatiable wanderlust; he prefers to stay home with a book. And somehow, ever since a fateful car share home from college many years ago, they are the very best of friends. For most of the year they live far apart - she’s in New York City and he’s in their small hometown - but every summer for a decade, they have taken one glorious week of vacation together.