After catching her boyfriend Chase kissing her roommate, Riley breaks up with him that same day. But Chase doesn't apologize. Instead, his friends start a betting pool on how long it'll take her to come crawling back, claiming she's never lasted more than thirty days. Riley refuses to give them the satisfaction. She doesn't just move on—she ends up with Mason, Chase's best friend, who is gentle and caring, nothing like the cheating Chase. As Chase goes from smug to panicked, he desperately tries to win her back, only to watch her smile brighter beside someone else. When the thirty days are up, he loses the bet completely—because he never realized she was always worth better.