Infidelity for a person is often as traumatic as the death of a spouse. Sometimes it can be more painful. Because after the death of a loved one or a beloved one, at least memories remain, and after infidelity?
Cheating brings a lot of suffering, because it is a well-aimed shot right at the core of the personality. Cheating on you tells you that you are worse than the other or the other, that your uniqueness is not worth much, you can easily be exchanged. Treason undermines the foundation of our existence. A close person, whom you believed and hoped for, suddenly turns out to be not close and unreliable. It's a terrible thing, more terrible than any fairy tale about a Gray Wolf, because it turns out that this Gray Wolf lived in the same house with you, you fed and watered him, and he looked at the forest all the time.