7x08 "The One Where Chandler Doesn't Like Dogs"

Phoebe sneaks a dog into the apartment; Chandler reveals that he hates dogs. Ross becomes obsessed with naming all fifty U.S. states in order to earn his Thanksgiving dinner. After revealing Tag broke up with his girlfriend and has nowhere to go for Thanksgiving, Rachel invites him to Monica and Chandler's apartment, and is hesitant on whether to tell Tag her true feelings.