  Us Weekly  View gallery   Justin Bieber outside Selena Gomez's
birthday party. (Fame Flynet)   The "Heartbreaker" singer, 19,
arrived at the gypsy-themed house party around 9 p.m., an
eyewitness tells Us, dressed down in a black-and-green letterman
jacket, dark jeans and white high-tops, with a small present for
the birthday girl.  PHOTOS: Justin and Selena: Their love
timeline  "Justin flew in specifically for the party on a day
off from his tour," the source tells Us. "He wasn't dressed in
costume, but carried a single red rose in his hand."  Other
celebrity guests included Julianne Hough, Nina Dobrev, Derek
Hough, Ashley Benson and Jaden Smith, among others. Best friend
Taylor Swift was performing at a show and unable to attend.  The
Hollywood pals took shots of chilled VeeV when Gomez's birthday
song came on, and noshed on Mediterranean food at the fun-filled
bash.  "Everybody danced and had a blast, especially Selena, who
was surrounded by her friends," an insider tells Us. Gomez's
birthday cake was sh