It’s a story of “I do”s and don’t’s: Police say a guest at a Long Island wedding tried to make off with the couple’s gifts.

The 18-year-old was awaiting arraignment Sunday after being arrested on a grand larceny charge.

He was at Larry and Joanna Williamson’s wedding Saturday at West Sayville Country Club in Sayville. Suffolk County police say the maître d’ got suspicious when he spotted the teen in the coat room, carrying a box full of envelopes that had been given to the couple.

The maître d’ alerted the bride. Police say the teen then ran to the men’s room, stuffed the envelopes in his clothes and darted out of the club.

Police say other guests trailed and stopped him.

The couple got all the gifts back.