Kiddy Bopper
Any person who watches the Disney channel, enjoys the music of Selena Gomez and Justin Bieber, and can't get enough of Zac Efron. It is mildly derived from the term "Teeny Bopper", where pop music is the main influence of style and the lyrics directly affect their thoughts and life's choices.
Underaged Girl: "OMG I can't believe I won tickets to Justin Bieber's concert! ZOMGWTF ILYBBQ!!1"
Immature Older Brother: "Dumb bi**h. You're such a kiddy bopper."
Immature Older Brother: "Dumb bi**h. You're such a kiddy bopper."