Here’s a 1963 home movie -- clip 3 of 4 -- of two sisters getting married at the same time in Michigan. Note that the sisters are marrying two different men and not each other. 

Begins with a sign that reads “just married.”

The mother of the brides argues with one of the brides by the table bearing two, large wedding cakes. The table is decked out with decorations, including flowers, ribbons, a white dove, and miniature figures participating in two different weddings; see the base of each cake for these figures.

Two bridesmaids pose before the cakes.

One of the brides poses with her new husband and a bridesmaid.

The other bride poses with her own new husband as people ready themselves behind them.

Both married couples pose for the camera along with the mother of the brides, a bespectacled priest, and a bridesmaid.

In the final shot, each bride kisses her father and her new  husband. The father smiles at the camera, looking proud of his daughters and happy to be present and celebrating this very special day.