Cheating Husband: What Would You Do?

March 24, 2008— -- Suppose you catch your best friend's significant other fooling around with another woman. What do you do? In previous episodes of "What Would You Do?" ABC News watched as one woman saw her best friend's boyfriend entangled with a beautiful stranger -- she shot him a warning text message and broke the news to her friend. And then there was the best man who caught the bride-to-be philandering with another man. He pleaded with the groom not to make the same mistake he had made.

Now, the stakes have been raised with a new dramatic twist -- one that makes telling the truth more complicated.

In this experiment, when Marina Ivanova met her friend Michael Boyle for dinner, she greeted him in high spirits. She had no idea that she was about to see her best friend, Natalia Volk, betrayed. Natalia's husband of one year, plastic surgeon Taj Khan, became awfully friendly with another woman who was actually an actor hired by ABC News.

Everyone except Marina was in on our experiment. Hidden cameras were rolling, and we watched and listened outside in our control van.

Michael, who was in on the experiment, told Marina he spotted Taj in the corner with another woman.

Confront or Stay Silent?

Marina glanced over, looking concerned. She strained her neck for a better look and wondered if Taj was having a business meeting. She realized she had a good view of Taj and the blonde in a mirror we strategically positioned on a nearby wall. Meanwhile, a column in the middle of the room shielded her from being seen by the cheating couple.

Through the mirror, Marina quickly recognized Taj. "Holy Moly," Marina said. "What should we do?"

Marina told Michael that he should go over and talk to Taj, because they are friends.

But, once again, ABC News added a twist.

Marina's friend, Natalia, whose husband appeared to be fooling around with the other woman, planned to join Marina and Michael at that very restaurant for dinner. Marina begged her friend Michael to go over and confront the cheaters.

Michael played along and said he did not want to get involved but thought they should tell Natalia. Marina's eyes widened. She clearly did not want Michael to tell Natalia. She urged him to approach the cheaters again because she is Natalia's friend and Michael is Taj's friend.

"It's a burden to have that kind of information," she said. "But, ultimately, yeah, you do put yourself at risk then that the person that you're gonna tell is gonna turn it on you."

"You know, maybe you didn't see it right, or they accuse you of wanting to wedge [the relationship] because girls can be nasty that way. If you're not that close of a friend, then you do put yourself at risk by telling them this kind of information -- they can attack you for it."

'The World Stopped for Me'

Finally, through his earpiece, we told Michael to go ahead and approach the cheaters. They discussed what Michael should say and Marina exclaimed that she could not even think straight. Anxiety and nerves took over.

Michael approached the cheaters and quickly returned to the table. He told Marina that Taj claimed she was merely one of his pharmaceutical representatives but Marina wanted to know why they were holding hands. She reiterated that she could not think straight.

Finally, our cheating couple headed for the door, right by Marina's table. She was polite and asked Taj how he was doing, giving our actress a light smile and a weak handshake. Taj introduced Jessie, our actress, as a pharmaceutical rep and they left soon after.

Marina continued to look worried and said she hoped Natalia would not walk in as Taj was walking out. "Holy moly, I've never been in a situation like this," she said. "I don't know what to do. I don't know what to talk about. I don't know. I don't -- I don't know. I -- that's it. The world stopped for me."

But Marina's dilemma had only just begun. Natalia was about to arrive.

She could not even calm her shaking hands.

Finally, Natalia arrived. She was happy and exuberant, unlike her best friend. Why? Yet another twist in the unfolding saga. It was a twist that made Marina's dilemma all the more excruciating.