Once upon a time there was an unsuspecting princess about to get the surprise of a lifetime.

Joel Lynch pulled off a magical “Beauty and the Beast” proposal for his girlfriend, Cara Szymanski, complete with Belle’s yellow dress, which he had sewn himself.

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

“We had watched it at one point early on, and she mentioned she always wished she could have the dress. And it was like, ‘Oh!’ A light bulb went on,” Lynch, 23, a graduate student at Iowa State University, told ABC News of the first time he realized Szymanski’s adoration for the classic Disney film.

“At first I was like, ‘I’ll just buy one, but then I realized it should be a labor of love,” he added of incorporating the homemade gown into the proposal.

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

Lynch began sewing the princess dress in October using a pattern he found online for a Belle cosplay costume.

“I started in October but the bulk of it I did over winter break,” he said. “We saw each other but I was able to hide it in closets and basements.”

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

The hardest part of the entire project was “getting all the measurements right,” which he managed to do quite accurately, leaving behind more than half of the 30 yards of silky yellow fabric he bought.

Lynch also wanted to be sure to get the aesthetics of Belle’s library scenes in “Beauty and the Beast” just right, so he reserved the vast periodical room of his campus library to pop the question.

“I owe a lot to the library and the librarians at Iowa State,” he said. “They were tremendous in helping get the room reserved and getting it set up.”

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

Physically getting Szymanski, who lives in River Falls, Wisconsin, to the library, wasn’t as difficult as it seemed.

“I actually asked!” she said. “I love to read and wanted to borrow some books.”

Once the oblivious bride-to-be arrived, she saw the magnificent gown and burst into tears.

“I just sobbed. Absolutely sobbed,” said Szymanski, 24.

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

It was at that moment she realized what was actually happening. Lynch helped her into the gown before the lovebirds danced the night away to the fairy tale’s iconic song, “Tale As Old As Time.”

“It was a beautiful moment and a beautiful memory and I look forward to every moment I share with him,” she said of her new prince. “One day, hopefully our daughter will be able to dance with Joel in the dress.”

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

Reflecting on what made her fall in love with Lynch, she said it was due to his “selfless and very romantic” personality.

“My absolute favorite part [of the movie] is when she is in the yellow dress walking down to the stairs and the Beast looks at her like he can't believe he's there with her,” she explained. “He looked like he couldn't love anything more. Joel seemed to master that look and I could definitely feel that.”

Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.(Courtesy of Leah Lynch) Joel Lynch pulled off a magical "Beauty and the Beast" proposal for Cara Szymanski complete with Belle's yellow gown.

The happy couple said they plan to incorporate subtle details from “Beauty and the Beast” into the wedding, but they are not sure of specifics yet.

One aspect Lynch will not be continuing, however, is his sewing.

“I probably don’t plan on doing much of that,” he said. “It’s a nice skill to have but I’m a little fatigued from sewing. It’s a long process so I’m done with that for a while.”

Disney is the parent company of ABC News.