S4·E11 The Runt Strikes Back

There's a dance on Saturday. Billie Jo and Bobbie Jo will only accept a date from either Steve or Don, the new young doctor in the valley. Neither Steve or Don have asked anyone to the dance yet. Billie Jo believes she has the right of first choice being the oldest. Left out is Betty Jo, who feels she has the right to be included in the dating discussion. Not wanting to take it anymore, Betty Jo decides to strike out on her own by moving out and getting a job. Through a series of misunderstandings, Billie Jo and Bobbie Jo wind up going to the dance with Eb and Betty Jo shows up with Steve and Don. It's not long before the girls are paired off with the boys they should've been with all along.