Selena Gomez, Jaime King, Emma Roberts, Ansel Elgort, Kelly Osbourne, Nick Jonas and Chrissy Teigen were just some on the exclusive guest list to attend Taylor Swift 25th Birthday Party! “So this is being 25 … #WHAT #bestbirthdayEVER,” she reported to Instagram posed up with Jay-Z, Beyoncé, Justin Timberlake, Sam Smith, Karlie Kloss, as they wore silly hats and ate pizza. Check out the gallery to see the star-studded festivities. Happy birthday Taylor Swift!