Star Spotting: Nick Jonas Celebrates The Big 2-1 With His Of-Age JoBros In Vegas (PHOTOS)

Nick Jonas rings in his 21st birthday with brothers Kevin and Joe.

The JoBros raise a glass to Nick at his 21st birthday bash in Vegas.

In honor of Nick Jonas' 21st birthday, we Photoshopped his face onto the cut and sculpted bodies of famously shirtless men. Why? Because about a month and a half ago, Nick blessed us with one of the greatest shirtless selfies known to man.

And to celebrate his own b-day, Nick did something way less weird. Gathering up a couple-dozen-strong crew, the "First Time" singer hopped over to Vegas on Sunday, and thanks to the youngest Jonas Brother's Instagram, we get to peek in on some of the late-night birthday reveling that went down!

Check out more photos from Nick Jonas' 21st birthday party in Vegas after the jump.

Just take a moment to pore over every handsome detail in the photo up top of Nick with brothers/ bandmates Kevin and Joe. The pocket squares! The coordinated-but-not-matchy-matchy suiting à la One Direction! The supersweet caption shout-out to missing JoBro Frankie ("Love my brothers miss you @t4nkofw4r"), who won't be able to go big in Vegas for another eight years! Two syllables: WE CAN'T!

Nick Jonas celebrates his 21st birthday with his girlfriend, Olivia Culpo.

Love seeing these two together. More, plz!

The same goes for this beyond adorable couple's shot of Nick with his girlfriend, Olivia Culpo (aka Miss Universe 2012). We were gonna make some obvious joke about how we're sure that it's the JoBro's "First Time" holding a glass of champagne #WinkWink #NudgeNudge, but, based on the super-earnest caption ("Champagne!"), we think our boy's been a little better than we gave him credit for.

Check out Nick Jonas' birthday cake!

Please put this in my mouth. Thanks.

At first we were a little confused by how #JustLikeUs this cake looks. Don't get us wrong, it looks duh-lish-uss, but, we figured that Nick-freaking-Jonas would've gone a little bigger for his big day. And then we noticed the bedazzled gemstones. Who knows, maybe it's even made from some celebrity-only brand of funfetti that replaces the candy bits with emeralds and rubies. (#ThisCakeCouldBuyAndSellYou)

Say hello to Nick Jonas and the Vegas crew!

What's up, Vegas crew?

We can only hope that 5 seconds after this group shot (including Kev's wife, Danielle, and Joe's girlfriend, Blanda) was taken, showgirls straight out of Iggy Azalea's "Change Your Life" video stepped into the frame and popped champy bottles all over the birthday boy -- or, we can only assume, rather? These pics were posted between 3 a.m. and 5 a.m.... Look out, Ma, we're drawing conclusions! HBD Nicky boy!!!!

Photo credit: Nick Jonas' Instagram