AceShowbiz -

Kevin Jonas has married his longtime girlfriend Danielle Deleasa Saturday night at a ceremony taking place at Oheka Castle in Long Island. Around 400 guests ranging from family members to friends, including Demi Lovato, were in attendance to witness their union as husband and wife.

Danielle wore strapless tulle and Chantilly lace Vera Wang gown and also put on a silk-and-crystal flower in her hair designed by Denise Leli. She was escorted by her father Thomas Deleasa when walking down the aisle.

"Kevin couldn't stop smiling," said Michael Russo, a celebrity event planner of Roses-n-Lollipops, who created a fairytale forest under heated white tents for the event. "The snow only made it look more like a winter wonderland," he stated.

Kevin and Danielle exchanged traditional vows and wedding bands by Jacob & Co which they designed for one another. Kevin's brothers/bandmates Joe Jonas and Nick Jonas served as his best men during the December 19 ceremony.

"We're so happy that we're finally married and we were able to share the special moment with family, friends and loved ones," the newly-married couple told People.