Again, when things end badly it is usually because there was sexual intimacy outside of a marriage commitment, but there are other factors that can contribute as well.
But to say that if we seek God we will get married is not. If one does , it makes the friendship awkward and even calculated. He calls us to pursue people who are pursuing Him like we are. This is the principle that I have to stress the most. In no way does it guarantee a loving, respectful, submissive, Christian wife who wants to please God by honoring me as her husband.