These are all categories and reason to which a spouse would cheat or have the notion to do so.

But I have to tell you that once they do know that their spouse is cheating, they want more information.

The people to whom she listens - virtually all of them women - are hoping to be excused from taxes they say they owe because their spouse, or former spouse, secretly cheated on their joint return.

True, these high-tech detectives probably cannot provide proof positive that your spouse is cheating, or figure out the mystery of the Maltese falcon.

Narrative is not the motivating factor in this story of a couple (Mr. Leung and Ms. Cheung) married to other people who find that their spouses are cheating on them.

"Men are coming into the office who are just as hurt as the women about the idea that their spouse has cheated," Ms. Friedman said.

Do you suspect that your spouse could be cheating?

"Many spouses cheat on their partners."