Joe Jonas & Blanda Eggenschwiler: Nick Jonas' 21st Birthday Party!

Joe Jonas cozies up to girlfriend Blanda Eggenschwiler as they arrive at his brother Nick‘s 21st birthday party at XS nightclub on Sunday night (September 15) in Las Vegas.

The couple was of course joined by Nick, his girlfriend Olivia Culpo, as well as Kevin and Danielle Jonas.

PHOTOS: Check out the latest pics of Joe Jonas

“Happy 21st to one of my best friends and a great brother @nickjonas,” Joe tweeted.

A few days earlier, Joe and Blanda were spotted enjoying lunch together at Cafe Gitane in New York City.

FYI: Joe is wearing Bally shoes.

15+ pics inside…