One possible factor is the desire to feel appreciated. When partners stop expressing gratitude or showing interest in one another's lives, one or both may begin to feel invisible.Someone outside the marriage may offer compliments, listen attentively, or create a sense of excitement. That attention can feel powerful, particularly when a person is already unhappy at home.
However, the early stages of a new relationship often involve fewer responsibilities and less everyday conflict. Comparing that excitement with a long-term marriage can create an unfair picture of what each relationship offers.
A healthy response to emotional loneliness is honest communication, not secrecy. Both partners deserve the opportunity to explain what they need and decide whether the relationship can improve.