Concert-Goers Sing "Happy Birthday" to Joe

At a concert performance at Hershey's Park, Kevin and Nick Jonas invited the audience to sing "Happy Birthday" to Joe for his 21st birthday, and it was all caught on video! Kevin's wife, Danielle, and a friend of hers brought out a cake to Joe on stage.

After the show, Joe tweeted ":)… Ohhh boyyy… That show was amazing!"

We're dying to know how Joe celebrated his birthday... So many doors open when you turn 21! ;)