That is a tough question.
I don’t really know; it is a very complex concept that seems simple, but of all the people I know who have gone through this, the story is never simple.
Do you have kids? Is the life of your children better off staying together or leaving? Not financially speaking, but emotionally. Is the person contrite? Does the person your spouse cheated with provide something essential you are incapable of giving, or not willing to? Did you neglect your spouse and is this the end product of that? Does love exist, in either relationship? Or both? Was it “just sex”? Could you have prevented it, in your actions? Is it habitual?
There are a million reasons people cheat and it is never black and white, meaning the person who was cheated on is usually part of the problem for the bad relationship, in most of the cases I know of personally, just like the person who cheated is at fault too.
I do know that infidelity is far more common than people think.
“The experts at Divorce Magazine note that about 45-50 percent of married women and 50-60 percent of married men cheat on their spouses.” (notice how they said “cheat”, and not, “have cheated”?)
I personally suspect that those numbers are low. I have heard that number as high as 90% of marriages/relationships, especially if you consider online relationships and all the variations of infidelity. Fuck, some people think masturbating to porn is cheating (i.e. Dr. Phil), or being a flirt with the guy/girl down the street. Some people think fucking somebody else not cheating, so I am a bit skeptical on the stats.
I do know this: (a) there are more Tumblr accounts than Twitter accounts, (b) that Pornhub, XNXX, and XVIDEOS are the 6, 7, and 8th most accessed websites in the US, c) that Chaturbate is in the top 20 and has over 400 Million Visit a month, which is nuts, since I have no idea what it is, and d) Tinder has 50 Million Monthly Users, which is like 1/6th of the United States.
So my answer is – I don’t know. I guess it depends. Not really helpful, I know. I do know this – I wouldn’t close up shop right away because of it. I would dig deeper and see if it was best for me to move forward or end it.