Lizzie and Sam are at the dive bar when the bitchy Mariposa sidles up beside them and intimidates Jason into buying her a drink. Afterwards, Lizzie and Sam overhear Mariposa on the phone and realize that Latin spitfire is just an assumed persona for Mildred, an ordinary girl who has learned how to channel her inner b**ch to get what she wants. The three women chat over coffee. Lizzie and Mariposa are both attracted to the same cute Waiter, and a challenge goes out – let the biggest b**ch win. Sam channels her inner b**ch with bike messenger Ryan and gets him to go home with her. They have wild, primal sex, but his interest fades in the morning when Sam inadvertently reverts to her nice girl self. Lizzie and Mariposa compete for the Waiter, but Lizzie can’t beat the master and Mariposa waltzes away with the prize. Later, a the dive bar, a Voluptuous Woman b**chily refuses to say where she bought her dress, so Lizzie cuts the label out of her garment. The dress is from a plus size shop - the Woman was embarrassed about shopping there. Lizzie feels guilty about her brazen behavior and apologizes. Sam goes home, and a deflated Lizzie stays at the dive bar. The Dirty Hot Guy sits down next to her, offers companionable silence, and buys her a drink.

Lizzie and Sam fight over Lizzie's acceptance of Drew's invitation to have drinks. Sam insists that this will lead to another reconciliation and break-up, and that it's time for Lizzie to end the relationship completely. It turns out that this time Drew just wants Lizzie to have her friend at the DMV fix some parking tickets for him -- he has reconciled with his cheating girlfriend. Sam bumps into Jason and lets it slip that she has a crush on him. Jason is free, since Lulu dumped him, and asks Sam out. As Sam readies for her date, Lizzie phones her to meet her at Drew's place, where they watch as a cop boots Drew's car -- Lizzie's revenge and a farewell to Drew. The girls celebrate at the dive bar, toasting their new rules: no more coercing guys to buy them drinks, no more young guys, no more b**ching, no more unrealized sexpectations, no more married guys, drinking contests or ex-boyfriends. Lizzie sees the Dirty Hot Guy and finally introduces herself; his name is Leo. Then Sam gets a text from Richard. She is torn, but opts for Jason. Lizzie and Leo also hook up for the night. Lizzie and Leo spoon contentedly after some hot sex, but sleeping in Jason's arms panics Sam, who gets up and leaves his place. She texts Lizzie to meet her -- she thinks she has just made a huge mistake...