S5·E20 The Joiners

Buffy wants to join a clique, but is dropped because she is younger by one year. Bill makes a deal with Shirley, the leader, that if he builds them a clubhouse, Buffy can join the club. After the clubhouse is built, Buffy is now a member, but Cissy wants her to run for secretary. The current secretary, Carol, wants to know why Buffy is in the club and Shirley tells her the truth and Buffy is out of the club.