He intended to present the ring on Sept. 8, but Ms. Porter woke up a little before midnight on Sept. 7 while Mr. Loigman was setting the scene, complete with a custom-made board game about their relationship, to propose. He regrouped, recited the Aristotle quote, “Friendship is a single soul dwelling in two bodies,” and asked Ms. Porter to be his wife. Ms. Porter, through what she called “hysterical tears,” said yes.

On July 7, before 100 guests at Mohonk Mountain House in New Paltz, N.Y., Mr. Loigman, in a black Kenneth Cole tuxedo, and Ms. Porter, in a Galia Lahav mermaid dress with dramatic train and vintage Tiffany earrings borrowed from her mother, met in a grassy garden under brilliant sunshine and an arch woven with ranunculus and roses. The Rev. Anthony Mizzi-Gili Jr., a Roman Catholic priest, performed the ceremony, as a 10-person wedding party, most showing their solidarity with the vegan couple by wearing no silk, leather or wool, looked on.

At a reception in an outdoor pavilion, the usual choice of chicken or fish was replaced with vegan options: rice noodles with coconut green curry, tomato basil risotto and tofu with Japanese sweet potato. Though many of the relatives who had criticized them in their youth for forgoing meat were in attendance, no one complained. In fact, Cheryl Rajewski, a Porter family friend who is lifelong meat-eater and chef, was fantasizing about the curry during cocktail hour. “I know it’s going to be delicious,” she said. “I can’t wait.”