My friend's divorce came through this week. It came through fast - a shock to to everyone who knew her and her husband as a couple. I thought they were the happiest childfree couple I knew. Married for nearly 20 years, they ran a successful fishing business together, took frequent road and boat trips, shared mutual hobbies, and loved their pets.

In spite of appearances, the husband in this partnership was growing less satisfied as the years went on. He didn't communicate his frustration to my friend, or perhaps, she wasn't listening to a more subtle form of language. The husband decided a couple of years ago, after his parents became terminally ill, that he wanted children.

He never confronted my friend openly about his changing attitudes towards having a family. Both have many siblings and, when they married, both were in agreement that spending time with their extended families was enough for them, without giving birth to kids of their own.

My friend never wavered in her commitment to living a childfree lifestyle, but clearly her husband's need for offspring began to change, along with his graying hair and widening waistline. This story illustrates how a well-established middle-aged couple can continue to evolve and grow in different directions. My friend is still shocked and surprised by the sudden breakup of her marriage. The most hurtful aspect of this situation is that her husband had been seeing a younger woman behind her back for several months prior to the decision to divorce.

Ironically, the husband discussed his urgent need to have children pretty openly with his girlfriend. They were planning to have a family - behind my friend's back - before divorce was ever discussed! The only clues he gave to his marital dissatisfaction were an increasing abruptness and an unwillingness to participate in this year's happy planning for summer road trips.

The outcome of the divorce has left my friend disillusioned, depressed and burdened with financial difficulties. She feels shell-shocked and plans to remain single for the rest of her life. I knew the husband before I met my friend. I'm stunned by his cruelty in starting a new family before leaving his old one. Perhaps, the main problem is that he didn't consider his childfree marriage a "family."

When my friend and her husband finally sat down with a marriage counselor prior to divorce, truths were revealed: her husband is suffering from a mid-life crisis and wants to have a child now to deter old age. His mother is dying and he wants to give her grandchildren while she's still alive, his ethnicity supports large families and now he wants a familial connection to his culture.

The lessons to be learned here are, of course, never to take any relationship for granted. Check in periodically with your partner: major changes occur even in long-term relationships. I've noticed that middle-aged childfree couples tend to assume both partners continue to maintain the same attitudes they had in their twenties, but that's not always the case.

Neither my husband nor I wanted kids when we first married, but several years later I did start to think about having a family. My husband was dismayed and ultimately I realized I that I'd have to leave my marriage to have children. I decided not to leave. I had health issues that made pregnancy difficult and I really valued our wonderful years of friendship. We talked about adopting some day, but that never happened, and after all these years we are still happy. Still, I force my husband to discuss children periodically. I want to know if his feelings are changing. These discussions annoy him, but my friend's experience confirms that I'm right in keeping the conversation alive.

It's very possible my friend's husband will try to return to her when he realizes he trashed a good long-term relationship to pursue an overly emotional urge for kids. Too late, he may find that marriage to a younger woman and taking care of babies are not for him. Sadly, he caused so much hurt through his dishonestly that a 20-year friendship lies in ruins.

Unfortunately, when people start to focus solely on having kids, adult relationships are not given equal status. Yet, adult relationships and friendships sustain us we grow older and, ideally, our spouse is our best friend: the friendship most cherished of all.

Laura Carroll (lauracarroll.com), author of Families of Two reminds us to stop thinking of ourselves as childfree couples and to consider enthusiastically what it means to be a family of two: a romantic partnership, a trusting friendship, a family. She writes, "A 'family of two' implies that you are a complete unit just as you are, with a routine that involves getting the dog groomed, planning get-togethers, and having some quiet time for yourself - instead of soccer practice, ballet lessons, and homework help. This is the lifestyle you've chosen, so embrace it completely!"

Carroll's advice makes good sense to me. Embrace all the wonderful, positive aspects of being a "family of two" and talk about them often with your partner. If one partner is beginning to change in attitudes towards children, talk openly about that too, no matter how difficult or painful. Nothing is more destructive to a marriage than procrastination and deceit.