1 Corinthians 7:4
The wife's body does not belong to her alone, but also to her husband. In the same way, the husband's body does not belong to him, but also to his wife.
We have become a highly individualistic type of society where we attempt to isolate ourselves from one another and where autonomy is one of the highest virtues. Unfortunately, we see this happening in our marriages as well. The man has his friends and his life and his hobbies while the wife has her job and her group and her hobbies. As a result, husbands and wives don't have very much in common aside from their children and don't really talk anymore. I believe the latest statistic I saw in regards to this was that married couples spend on average 14 minutes a week in meaningful conversation with one another. Isolation from your spouse often leads down the pathway that ends with disconnect and divorce.
Now I'm not advocating that men and women give up their friends and their hobbies, only suggesting that a good amount of time be placed aside for shared hobbies and interests that can help spark the growth of your relationship with your spouse.
Paul says in this verse that once you are married, there is no more any autonomy. Now when you throw out your back, we throw out OUR back. And when you seek to make decisions, WE need to discuss what WE will do. Your life and the life of your spouse are so closely linked that it should be impossible to tell where he ends and she begins and vice-versa. You belong to your spouse in a way that lays autonomy aside and replaces I with We and Me with Us.
I mean, this is the way God planned it in the beginning: "For this reason a man will leave his father and mother and be UNITED (one, joined) with his wife and they will become ONE (singular, not-divided) flesh." Genesis 2:24