Reuben has discovered a new singing act, 14-year-old twin brothers Andy and David, and he brings them to live with the Partridges until they cut their first record.
The boys have a crush on Laurie and she doesn't want to hurt their feelings and agrees to go out with them. The family thinks Laurie's double-crush is cute and kids her about it.
Andy and David become serious and tell Laurie she has to choose which one of them she wants to date. They decide to help her in the decision by not dressing alike anymore and breaking up their singing act to become more individual. Now everyone realizes how serious this has become and Keith and Danny try to help Laurie but the plans backfire. The twins are more in love than ever. Finally Shirley enters the picture and explains to the boys that they will get over their crush but they shouldn't sacrifice their friendship over this. But this time even Shirley seems to fail.
Laurie gets up enough courage to confront the boys but they have changed their minds. The crush is off and they've decided not to let a girl come between them. Shirley's little talk worked after all. The boys make the recording for Reuben and it looks like they have a hit on their hands.