The setting sun on Long Beach Island’s Spray Beach was truly the perfect backdrop for a family celebrating 40 years of unwavering devotion and closeness. A reflection of the sun’s waning light off the sand and the sea seemed to highlight what has become an extraordinary love story, beginning some 50 years ago on Valentine’s Day, 1973. They were both in the sixth grade when my future brother-in-law, Mark, asked my sister, Mary, to be his valentine. They married on July 25, 1981.

Celebrating their 40th anniversary on July 25, Mark and Mary Fanning of Dutchess County, N.Y., kicked off their annual…