Since We Were Friends — Zoe Haslie

Sixteen-year-old Regan Clark only longs for the summer camp trip her dad takes her and her three brothers in each year. But everything changes when the unimaginable happens—her best friend, and acquired fourth brother, Harper, turns into a big cheat and she gets cast aside.So when school starts again, Regan finds herself friendless, struggling with soccer practice and on the verge of failing math. On top of that, Harper's own issues lead him to move in with the Clarks, which makes it next to impossible to hide all the bad blood between them. But meeting Sophie turns into a mindblower, for Regan's introduced to the strange world of girls she's been missing out until now. And, much to her dismay, she soon finds out what hurts the most about losing her best friend—to be secretly in love with him.