Affair Can Cut Much Deeper When There's an Emotional Bond

In the Sanfords' case, it's more challenging because the personal details have become so public, offering a view of an emotional and physical involvement.

"Any time you take energy away from a marriage, especially in such a high-profile stressful position (as the governor), which also takes energy from the marriage, there is little left over for the marriage," Savitz said. "I would suspect that it has been a lonely place for Jenny Sanford to be in, other than having her children and investing in them."

The Sanfords have four sons.

Children often are caught in the middle in these situations the toughest place to be, therapists say.

"They love both parents. The last thing any child wants is to see their family broken up," Savitz said. "They take on a greater responsibility than they should have to."

"Teenagers, we often find, are the angriest, least forgiving and the most upset by it all. The kids can often be angrier than the spouse who has been cheated on," Gehard said. "If their father has talked about character and values and being a good person ... teens, in particular, are rattled quite a bit by an affair by a parent, especially when it's so out of character for their father."

For Maria, the woman in Buenos Aires, the road will be tough, too.

"It's quite a triangle," Savitz said. "She's hurting also. You have to admit the end of a long-term ... relationship. There's a void in her life, too, assuming it's over."

Olson said that in situations like this, the mistress often is abandoned "because she is seen somehow as the bad guy, as the perpetrator of this; that somehow this wouldn't have happened if she wasn't around. That's often unfair. She needs real support and care as well."

Gehard agreed, and said the situation is even more complicated because the affair has been made public worldwide.

"If she was in love, her heart's broken. And anybody who has had her heart broken knows that feeling," she said. "Plus, she has the humiliation. And she cares about this person. It can be very traumatic to be going through this.

"It's heart-wrenching."