The answers to this question are many and varied. It really depends on the couple involved and on the extent of the affair. If one spouse refuses to end the affair and says he or she is in love with the other person, it’s nearly impossible to salvage the marriage. Some articles tell the dishonored spouse to compete with the other woman or man, but that’s some tough competition.
The other person has it made because he or she can always put on the best face during the limited amount of time that the two are together. Your spouse only sees the picture perfect image the other person presents but doesn’t see the true person under stress, when weighed down with responsibility, when tired, sick, or cranky.
If your spouse actually wants to save the marriage, he or she will have to end the affair first. You cannot restore your marriage with another person between the two of you. I saw the affects of such an attempt recently with long time friends. The husband insisted on still seeing the other person, trying to make up his mind between her and his wife. The wife stood by, hoping he would choose her.
The longer the affair went on, the more he compared the two women. It’s never a fair comparison, and the spouse will rarely win. When he did actually give up his mistress for a short time, it looked as if the marriage might be saved. However, as soon as his wife had one bad day or did anything he didn’t like, he’d compare her to his mistress. “She would never do that. Why can’t you be more like her?”
At this point, my friend decided her marriage was over. I felt bad for her, and I hate to see any marriage end, but I don’t know how she held out as long as she did. I’d kill the guy (not literally of course).
In other cases, I’ve seen marriages survive affairs when a spouse was truly penitent. A woman I know cheated on her husband, a one-time deal, which only made her realize how important her husband was to her. They were able to salvage their marriage and rebuild the trust over time, and they are still happily married.
The ultimate answer to the question in the title is yes. A marriage can survive an affair. The caveat is this: It takes two; it can survive if both spouses genuinely want it to and they both work together toward that end.