Many of the influences that could cause a relationship failed I will give one example of couples who no longer have sex will feel distant and even really keep away from each other because there is no emotional bonds are strengthened in between the two. If you've put it this way, do not consider trivial because it would be bad if the marriage took place at life in a long time
It's one of the example I mentioned above many other causes such as economic problems of personality is not the same