When Kevin spoke about the proposal, he said: "She said yes, yes, yes like 500 times super fast in a row."
Danielle, who met Kevin in May 2007, added: "It still feels like a dream."
The 21-year-old Jo Bro admitted he was nervous about popping the question.
He said: "It was tough performing last night, knowing that I was going to ask the biggest question in my life to the most amazing girl in the world."
Joe and Nick spoke of their joy at the engagement, saying on their Twitter page: "Congrats big brother... Dani welcome to the family, we can't wait to have you join us on the road!"
Aww, what a sweet couple they will make. Congrats Kevin and Danielle!!
see? the second one. told ya there will b more! kevin proposed....