At the music video shoot, Nat is confused why the director is attempting to make his song "Catch Up With The End" humorous because that's not how he intended it to be. Rosalina thinks that Alex so funny, and she thinks that stand up comedians are so brave. Because of this, Nat decides to perform at a stand-up comedy club, which initially fails. In the end, Nat and the band perform his song at a night club featuring George Lopez as the opening act.
Dad goes away for an accordion convention, leaving the kids to have a weekend long slumber party with only Jesse to supervise. When the kids are faced with the ensuing mess, Cooper suggests they hire a maid to help with the clean up. Instead, they get Betty, a "cleaning specialist", who watches old movies and drinks non alcoholic mint juleps while she instructs the kids on how to clean. The kids' plans to fire her are flummoxed when Dad gets home and falls head over heels for her.
One evening before bed, Alex asks Nat to write a song for the band to perform at the Foster Kids benefit that he can dedicate to his new friend Juanita. Nat agrees, but the next morning, both boys wake up with a song in their heads. Later that day, the boys are shocked to realize that they've both written the exact same song, and each accuses the other of copying it, Meanwhile, the boys are horrified when Dad announces his intention to deepen his commitment to Betty.
The Naked Brothers Band and another band, the L.A. Surfers, find themselves competing in a "Battle of the Bands" charity event benefiting Little Kids Rock. Rosalina starts to fall for the L.A. Surfers' lead singer, Bobby Love. It annoys Nat that Rosalina hangs out with the opponent's lead singer. It turns out that Bobby is just dating Rosalina to get to Nat and is lying about everything, i.e, his British accent, not writing his own songs, etc. Nat and Bobby fight and declare at a press conference that the charity event is now a competition and the losing band's ...
After Nat' unsuccessful attempts to tell Rosalina the truth about Bobby, he and the band make fun of her and she quits. She tells Bobby what happened, then throws away her music into the garbage, and when no one is looking, Bobby pilfers it. At the concert, Bobby's band plays Nat's new song that he stole from Rosalina. Bobby's fake identity is revealed. The Naked Brothers Band plays Nat's new song "Girl Of My Dreams", dedicated to Rosalina and they then win the Battle of the Bands.
The concept behind their new video shoot is that there are clones of all the band members that are taking over. Alex takes this idea to heart and becomes terrified that everyone around him is actually an alien clone.