 The video begins with Montana entering Lilly Truscott 's , portrayed by Emily Osment , Sweet sixteen at the Santa Monica Pier . Montana is attempting to explain the scenario to Osment 's character , saying , " I 'll make it up to you , I promise . " Then Truscott ( Osment ) says , " You will never make this up to me . " Montana is being overwhelmed by fans , which proceed to lift her to a stage and perform the song . Throughout most of the video Cyrus ' character performs the song with background dancers , a band , and Steve Rushton on the electric guitar . In the conclusion , Rico Suave , portrayed by Moises Arias , emerges from a massive birthday cake that explodes on the crowd . 
