This family is one of my many case studies on opening the door just an inch to the devil and seeing the havoc that results throughout the generations.
Way back before my aunt and uncle got married, my grandparents and my aunt's parents all got together to talk about the prospects of marriage at such a young age, and being in love but ill-suited for one another. This is the only time I have ever heard about my grandparents voicing a dissenting opinion about one of their children getting married. My grandparents were both one of ten children and had seven surviving children of their own, so they weren't strangers to ups and downs or seeing things working out despite the odds...or failing even with best intentions.
Both sets of parents strongly cautioned their children against this rash marriage, but my aunt and uncle "were in love" and no amount of parental pragmatism was going to influence their head-strong choice to be married -- married now.
Needless to say, a dozen or so years later, after four children, the separation happened. Not long after, once both of my grandparents had passed away, came the divorce and subsequent remarriage by both my aunt and uncle to other previously married, previously Catholic, folks.
And also needless to say, three of their four children have had terrible track records when it comes to marriage and life choices.
But, the real point here is the first instance of divorce and how begins to cascade down through the generations. In every branch of my family, once a divorce happens, it is practically endemic, always tragic.
One doesn't even need to go back to the saints of antiquity or the Church Fathers to read about how marriage and divorce are to be viewed. It is only in the last century, maybe the last few decades, that marriage has been regarded dispassionately and as a contract. C.S. Lewis, for instance, writes seriously about marriage in his Mere Christianity, and with wit in The Screwtape Letters.
"The idea that "being in love" is the only reason for remaining married really leaves no room for marriage as a contract of promise at all. If love is the whole thing, then the promise can add nothing; and if it adds nothing, then it should not be made. The curious thing is that lovers themselves, while they remain really in love, know this better than those who talk about love. As Chesterton pointed out, those who are in love have a natural inclination to bind themselves by promises. Love songs all over the world are full of vows of eternal constancy. The Christian law is not forcing upon the passion of love something which is foreign to that passion's own nature: it is demanding that lovers should take seriously something which their passion itself impels them to do." (Mere Christianity, Chapter 6, Christian Marriage).
"...they (Protestants and Catholics) regard divorce as something like cutting up a living body, as a kind of surgical operation. Some of them think the operation so violent that it cannot be done at all; others admit it as a desperate remedy in extreme cases. They are all agreed that it is more like having both your legs cut off than it is like dissolving a business partnership or even deserting a regiment. What they all disagree with is the modern view that it is a simple readjustment of partners, to be made whenever people feel they are no longer in love with one another, or when either of them falls in love with someone else." (Mere Christianity, Chapter 6, Christian Marriage).
Because marriage is a reflection of the Trinity, the devil wants to destroy it. Once the couple begins to drift from the Church and are no longer receiving graces from the sacraments, it's like opening the door, knowing there are wolves outside.
And, everyone who has seen a horror movie knows you never open the door.