S1·E9 The Big In with the In Crowd Episode

Dee Dee invites Mona to a ""girls night"" with her friends, but Mona instantly feels out of place amidst the ritzy women. When Dee Dee gives Mona an expensive purse, Mona deduces that her half-sister is trying to make her over. Meanwhile, Spencer is attracted to one of Dee Dee's friends.