Ignore it. One reason to do so, said workplace consultant and dearpeggy.com founder Peggy Vaughan, is that most affairs do tend to "run their course" in six months to two years. "The more time [the couple] spends together daily, she said, the quicker the affair will end. "It's biologically based. Fascination and newness wear out."

Talk to the person/s. But know that this could be ineffective at best, risky at worse. "I've heard from people [in affairs] who are suddenly called on the carpet and they say, 'I'm doing my job, I've been here for X number of years, it's none of your business.'" Worse, of course, is if that person is your boss. "He or she is not going to listen to you," Vaughan said. "Are you prepared to lose your job being the troublemaker?"

Go to H.R. or your boss (assuming neither is the offender). Focus on the company's bottom line, not your own feelings. Saying "I'm personally offended" will get you nowhere. It's best if you can discreetly find a co-worker or two to join you, so this doesn't look like a personal vendetta. Point out that this affair is threatening the company's professional reputation and is interfering with productivity.

What's unusual about Mark Everson's high-profile firing from the U.S. Red Cross, Vaughan believes, is that the "top guy got fired instead of the female underling." She thinks public pressure was the reason. "Nothing would have happened if they didn't have a lot invested in their image. They had to do the 'right thing.' If they could have kept it quiet, they would never have fired the top guy," she said.

Update your resumé. Sometimes, the pain of staying is worse than the uncertainty of getting out.

GAIL ROSENBLUM