They've fought over guys, sorority elections and who gets the last Cheeserito. Casey Cartwright thought that made her and her ZBZ little sis Rebecca Logan closer. But when Casey's ex, Evan, nominates Rebecca as the next Omega Chi fraternity Sweetheart and Rebecca hesitates, Casey vows to play hardball. ZBZ's status on campus depends on Rebecca winning that title. It's time for some sisterly guidance.

Meanwhile, Casey's brother Rusty wants to create a truly spectacular legacy for his fraternity, Kappa Tau, and KT prez Cappie is hoping to live up to Casey's expectations for their fragile new relationship. The pressure is getting to everybody. When Casey goes overboard trying to advise Rebecca on how to win Sweetheart, things reach the breaking point. Will a surprise finish to the competition shake everything apart, or is it just the shock needed to bring best frenemies together?