From the award-winning author of Simon vs. the Homo Sapiens Agenda comes a funny, authentic novel about sisterhood, love, and identity. "Heart-pounding, honest, and hilarious. I can't put this book down." - Stephanie Perkins, New York Times bestselling author of Anna and the French Kiss. "I have such a crush on this book! It's not just a must-read, but also a must-re-read." - Julie Murphy, New York Times bestselling author of Dumplin'.

Seventeen-year-old Molly Peskin-Suso knows all about unrequited love. No matter how many times her twin sister Cassie tells her to get it together, Molly can't bear the thought of rejection. So she plays it safe. Plus-size girls always have to be careful. Then a sweet new girl enters Cassie's orbit, and for the first time, Molly's cynical twin sister is a lovesick wreck. Meanwhile, Molly is not dying of loneliness at all—except for the moment when she actually is. Luckily.