After 70 years of marriage, Paul Miller is still madly in love with his wife Imogene, and it shows.

At the couple's June 10 anniversary party in Hot Springs, Arkansas, Paul serenaded Imogene with a rendition of "Let Me Call You Sweetheart" by Bing Crosby, holding her hand all the while.

"I started practicing so it would sound just right," Paul told ABC News. "I didn't just reach up out of the clear blue sky to choose it."

The couple officially celebrated their 70th anniversary on June 15, which was also Paul's 90th birthday.

Video of the sweet song was shot by Robin Vermeer Bobo, who has known the Millers since she was just 2 years old and even lived with them for a time. According to Inside Edition, Paul and Imogene took in many kids and families in need over the years.

Robin said the Millers have been wonderful role models to so many.

"They've been together all of those years," she told Inside Edition. "He sings to her a lot. He tells people she's the most beautiful person he's ever seen."