Calling it off

Calling it off (Mike Kemp, Getty Images/Rubberball / February 21, 2012)

Friends and family with concerns about the relationship also should speak up long before they're asked to forever hold their peace at the ceremony, Gauvain said, because their outsider's perspective is often a clearer one.

It's important to set aside the question of the party while sorting through the relationship issues because any trauma from canceling won't hold a candle to a failed marriage, Gauvain said.

Derailing the party plans

But once the wedding wheels are set in motion, it's difficult to veer off course.

With the invitations sent and flights booked for out-of-town guests, Emma Wilhelm and her fiance plowed ahead toward their wedding despite her mounting concerns that they'd been fighting a lot. Reasoning that the stress of wedding planning was making them testy, she hoped it would get better once they married.

Wilhelm's anxiety grew as the wedding date approached — during that time, the priest who administered their pre-marriage counseling informed them they had set a record low score for financial compatibility — but she dismissed it as typical jitters. As she walked with her parents down the aisle on her wedding day, Wilhelm, 27 at the time, remembers sobbing inconsolably.

"It was not normal sentimentality," the Minneapolis writer, now 34, recalls. "I couldn't recognize it at the time, that maybe I should turn around and walk out."

Fourteen months later, with their fighting grown dysfunctional and several months of couples counseling unable to help, Wilhelm and her new husband divorced. If she could change anything, Wilhelm said, she would have insisted on a longer engagement so that they could have cultivated a healthier relationship (they got engaged after six months of dating and married six months after that).

"It was totally humiliating, absolutely horrible for my self-esteem," said Wilhelm, who runs the blog "There's a lot more judgment (in divorce) than if you just said, 'My fiance is not for me.' "

Kindness matters

Those who do decide to walk away owe it to the other person to do so kindly: in person, firmly, leaving no room for negotiation, said therapist Mira Kirshenbaum.

It should not happen the way it did to Josh Opperman.

Three months after he proposed to his girlfriend of four years, Opperman returned to their New York home after a weekend away to find that she had moved out. There was no note, just the engagement ring sitting on the dining table, he said.

"At least have a discussion instead of leaving me blindsided," said Opperman, who was 26 at the time and is now 34. After ignoring his frantic calls for a day, his fiancee finally answered her phone and told him she was seeing someone else.

Opperman also discovered that selling back the engagement ring would get him just a third of what he paid. That led Opperman to found, a marketplace for secondhand engagement rings where jilted brides and grooms can recoup 50 to 80 percent of their ring's original cost and buyers can get authenticated jewelry at steep discounts.

"Looking back," said Opperman, now married with a new baby and a booming business, "it was the greatest thing that ever happened to me."

— A.E.R.