If you confront the person at this stage, either you will be targeted as the problem or he or she will lie or deny anything and everything, which will confuse, confound and temporarily help you to deny your intuition and suspicions. Meanwhile, the betrayer is readying for a transition out of the relationship. They do not seek out committed relationships, they are philanderers. They proceed from one light-hearted tryst to another, whistling, enjoying themselves and their risk taking while proclaiming interest in remaining married. They are always looking for a new adventure.
Infidelity is their way of life.
Living with a philanderer is demeaning, diminishing, and damaging to self-esteem and the soul. If your partner has been involved in more than one affair, consider that this may be their permanent pattern and act accordingly. The dissatisfied partner feels helpless, hopeless, and unable to get the partner's attention or the change they desire. An affair is a convoluted solution to a marital dissatisfaction but it does get attention. In relationships people become sloppy in their treatment of each other.