Last Year’s Mistake by Gina Ciocca

Before:
Kelsey and David became best friends the summer before freshman year and were inseparable ever after. Until the night a misunderstanding turned Kelsey into the school joke and everything around her crumbled – including her friendship with David. So when Kelsey’s parents decided to move away, she couldn’t wait to start over and leave the past behind. Except, David wasn’t ready to let her go…

After:
Now it’s senior year and Kelsey has a new group of friends, genuine popularity, and a hot boyfriend. Her life is perfect. That is, until David’s family relocates to the same town and he shakes up everything. Soon old feelings bubble to the surface and threaten to destroy Kelsey’s second chance at happiness. The more time she spends with David, the more she realizes she never let him go. And that maybe she never wants to.