Is betrayal the ultimate challenge in a long term relationship?

I was thinking of the preparation we receive before marriage about long term relationships. I was a young adult in the 90s and I remember hearing about challenges. Some of the possibilities were deaths in the families, financial difficulties and illnesses. Infidelity was not supposed to be tolerated. 

After sailing through infidelity, I have learned that infidelity is indeed a deal breaker and that it transforms both the betrayed and the betrayer. I also learned that cheating with an affair partner or porn are in just one of the modalities of breaching trust. There can also be other physical or psychological forms of abuse, theft and other types of betrayals. 

Speaking for myself and for many of the peeps I have had conversations with about infidelity and affair recovery, there are two kinds of people: those who are loyal and those who are willing to build compartments in their life to escape the challenges of marriage.

Many of us have been betrayed while being gaslit by our spouse. It was not supposed to affect our marriage because it was just something "for fun". 

I don't think there is any challenge that a long term relationship can face that compares to betrayal. In love, and in business, we make a commitment to build a life together. And we work for it. Many of us support our partner so they can develop their full potential. It is good for the family/business and it makes us happy to see our beloved/partner fulfilled. 

We are willing to take care of them when they are unwell, we live frugally when money is scarce and we mourn with them when they lose a parent or a member of their own family. But a lover? That is a whole new level of challenge. 

If you are in pain because of a betrayal, know that you are only feeling what is expected under the circumstances. No one can understand or imagine the pain a betrayed spouse experiences until they go through it themselves. 

Know that is is not about you. There is nothing you could have done to prevent your spouse from cheating. If there was a problem, s/he could have communicated with you and decided to separate before betraying you. Nothing justifies having a spouse who lives a double life. The lie is 100% on them.

I do believe that betrayal is the greatest challenge a long-term relationship can face. It is one that can be avoided and that's why it hurts so much. Illnesses, deaths and financial losses can escape our control but lying and gaslighting are in a next level of deceit.