Happy 21st Birthday Nick Jonas!

Happy 21st Birthday Nick Jonas!

Hes practically grown up in the public eye, and today (September 16) Nick Jonas can legally buy a beer, as hes officially 21 years old.

Last night (September 15) the Who I Am rocker celebrated the occasion at XS Nightclub inside the Wynn Las Vegas along with his new girlfriend, 2012 Miss Universe Olivia Culpo.

Also along for the ride were Nicks brothers Joe Jonas and Kevin Jonas and their ladies Blanda Eggenschwiler and Danielle Jonas, and everyone looked so snazzy!

Jonas and Culpo raised eyebrows with their very public kiss at the US Open earlier this month, followed by Olivias Instagram post, “So serious <3 @nickjonas." Looks like all three Jonas boys are spoken for.