Courtney Greenhalgh of Cinnaminson, New Jersey, uploaded a video on her Facebook page showing the adorable interaction between her 21-year-old sister and her sister's boyfriend, who both have Down's Syndrome.
Greenhalgh's family held a luncheon on June 25 with their closest relatives and friends to celebrate Ashley's 21st birthday and high school graduation.
"Among the crowd was my sister's boyfriend, Danny," Greenhalgh wrote. "Danny and my sister have been dating for two years and couldn't be more perfect for each other. They both have each other's best interests at heart.
"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 and that he only has eyes for her."
Greenhalgh said that Danny saved up his own money from his job to give her sister "a beautiful, diamond promise ring."
Facebook users were moved by the interaction between the two love birds.
"This is literally the cutest thing I have ever seen in my entire life. They are so sweet," wrote a Facebook user.
"I cried watching this ..I loved it," wrote another.
Watch how Ashley responds to Danny as he presents the promise ring to her in the video above—which has accumulated more than 24,000 views.