Many relationships, whatever the case (love, work, friendship, etc.) end up breaking, when you feel, one of the betrayed parties and a betrayed person, they rarely forget.
People, usually try to forgive, but always have the thorn in what happened, a person usually forgives once, but when they give a second chance, and that opportunity is also betrayed, they simply break with the relationship they have.
People should be cautious and, with caution, observe the attitudes of others and, depending on the analysis they make, see if they can really trust someone.