Courtesy of Jacob & Co. inset: Courtesy of Kevin Jonas

When Kevin Jonas asked his girlfriend Danielle Deleasa to marry him early Wednesday morning, she was too stunned to notice the one-of-a-kind diamond ring he designed for her. "I didn't see the ring for a while because I couldn't believe what he just asked me," Deleasa told PEOPLE. "I was looking at him, like "Are you serious? When he pulled out that ring, I was like 'Oh gosh.' I said something like 'Oh my God,' and then I started crying." But once she wiped away her tears of joy - and said yes over and over again - what she saw before her was a three-carat cushion-cut diamond set in platinum above double shank band with 210 round pave diamonds (pictured here), according to Angela Arabo, Jacob & Co vice president, who worked with Kevin to design the ring. The star "had done his homework," Arabo said. "He knew exactly what he wanted." The two collaborated over the phone and email. "When he got the ring, he called me and said it was the most beautiful ring and it was exactly how he imagined. He was really excited. He couldn't wait to propose to her." Kevin Jonas, 21, proposed to Deleasa, 22, surprising her at her doorstep early on Wednesday morning - flying overnight after a Jonas Brothers concert in Vancouver. Arabo talked to the happy couple Wednesday night and wished them the best. "He was very happy and thrilled. Danielle is very happy and she has the ring on right now." No wedding date has been set yet. Right now, Kevin told PEOPLE, ""We're just ready to celebrate with friends and family and of course all our fans." - Sharon Cotliar