For this young couple, love knows no bounds.

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A video shows Danny Griffiths, who has Down syndrome, giving his girlfriend Ashley Greenhalgh, who also has Down syndrome, a promise ring for her 21st birthday — and her reaction is priceless.

To celebrate Ashley's birthday and recent graduation from high school, her sister Courtney Greenhalgh said they hosted a small gathering with their friends and family two weeks ago.

When Ashley came to open her gift from her boyfriend of two years, she could hardly contain her joy.

In the video, she giggles as she reads a card he wrote for her birthday and another for her graduation.

She grabs a bear out of gift bag and finally, she pulls out a tiny box and begins unwrapping.

"It's a ring," she squeals in excitement. "I'm going to be married!"

Her sister later wrote in a Facebook post, "Danny and Ashley talk about getting married in the future; while they know that the timing isn't right just yet, Danny wanted to go out of his way to let my sister know that he will always be there for her."

Even though the diamond Danny saved up to buy was a promise ring, he kneels to one knee and asks, "Will you marry me? Will you be my wife?"

The big reveal came after meticulous planning between the two families, who came to an agreement that although it may be early in their lives, the couple is meant to be.

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Danny told InsideEdition.com that in the following years, he plans to work hard and save money to take care of Ashley. They plan to be married in four years, with plenty of time to prepare for the big day.

"I couldn't be prouder as a big sister," Courtney told InsideEdition.com. "She's accomplished so much. The whole world is in front of her and she can do whatever she wants."

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