Patience is a virtue many people possess, and it has often been that factor that has saved a relationship in the midst of chaos. A person upset when tragedy strikes can find their partner is a rock of stability, and they lean on them until they can deal with the emotional outfall. While it suits them well when life keeps throwing things at them, it can become an issue between a steadfast partner and one who has a lack of tolerance for almost anything in life. Even those who have exhibited a great deal of patience in the past may use up all they have.
When one person in a partnership is intolerant of something, a good spouse might find ways to exclude it from their life. The person they love might find broccoli disgusting, so they will not serve it for dinner. If one of them has found they will do anything to avoid going to the beach, mountain vacations might be the plan for a lifetime. Each of these scenarios are because one person refuses to in any way tolerate something, and their partner is willing to forego them to make the relationship work.
There are times when being with another person eventually tries the patience of even a saint, and constantly refusing to be tolerant can do it. Many people have someone they do not like, but they can continue to object to new people because they get a thrill when their partner drops them from the social calendar. This is isolation behavior at its worst, and it can destroy the relationship over time.
For those who have put up with everything their partner has tossed their way for decades, finally pushing back can be a shock. The couple might be able to work out their differences, or their relationship might finally end.