Editor's note: Married professor Pamela Haag is the author of "Marriage Confidential: The Post-Romantic Age of Workhorse Wives, Royal Children, Undersexed Spouses, and Rebel Couples Who Are Rewriting the Rules."
(CNN) -- You've tried marriage therapy. You've tried date night. You've tried attitude adjustment, and tricking yourself into ignoring the discontent ("Just suck it up. ... Everyone feels mediocre about their marriages. ... Stop being selfish and whiny").
Now, you and your spouse are tottering on the brink of throwing the baby of your amiable, functioning but listless marriage out with the bath water of its flaws.
There's a part of your soul that isn't nourished in marriage, and it's too big a part to live without. You've tried, but you fear that you're in the wrong marriage, however wonderful your spouse may be.
You're in the group of "low-conflict," amiable but less than fulfilling marriages. Marriage researchers estimate that they contribute the lion's share to divorce court each year -- anywhere from 55% to 65%.
It's not the couples who throw dishes and scream at each other (although you'll probably meet them in divorce court, too). It's the low conflict, semi-happy marriage.
And, when it divorces, acquaintances are apt to say, "Wow, I never saw it coming. They seemed like such a happy couple."
If you're in an unhappy but low-conflict marriage, is there any alternative to divorce or glumly sticking it out?
Yes. Change the marriage instead. Take a fresh look. Maybe the problem is not you. Maybe it's not your spouse. Maybe it's marriage, and how we "do" marriage that's the issue.
There are thousands of books to tell you how to fit yourself, the square peg of a discontented spouse, into the round hole of the institution of marriage. But there are few if any that flip the question, and consider how to change marriage so that it fits us.
Here are some ways, modest and monumental, that 21st century marriages have carved out a third path between a semi-happy marriage and divorce:
If it's possible, consider separate bedrooms. You'd be surprised how the creation of privacy and nonmarital spaces in a marriage might help. Already one in four Americans sleep in separate bedrooms or beds from their spouses. The National Association of Homebuilders predicts that by 2015, 60% of new homes will be designed with "dual master bedrooms."
Try a "marriage sabbatical." It's different from a separation, which has no time limit, or a divorce. With a sabbatical, a marriage hits the "pause" button on itself. It creates an intermission, where spouses spend time apart, for months or even a year. It's a way to reconcile the stability of the semi-happy marriage with the need for some happy-happy personal growth time.
Update and rewrite your vows to reflect reality. What if you rewrote your marriage vows, and contract, every few years to reflect concrete, tangible stages in your marriage? I interviewed a couple who did this. If you're contemplating divorce, you might try to write up a new agreement for, say, the next three years, to create vows, promises and rules that are actually pertinent to your fragile marital situation.
A politician in Bavaria even proposed that marriage contracts amortize automatically after seven years, although the idea didn't go anywhere. It might be a harbinger of the future, a planned obsolescence for marriage.
Consider divorced cohabitation. Some divorced couples still maintain a household, usually to provide stability for their children, but enjoy the (discreet) privileges of any other divorced spouses. This alternative has only grown since the 2008 recession, because semi-happy marriages that might otherwise have divorced are now forced to stay put in the same house, because they can't afford to get divorced, or they can't sell their house.
Could you practice "the new monogamy"? What about the perhaps most audacious idea, but one that is working right now for some marriages: Would you have a conversation with your spouse about the possibility of other attachments, of open, "ethical nonmonogamy" as an alternative to divorce?
Most say it "never works," but the fact is that there are happy, secure couples right now who do it in some form or another. If you're at a gathering with 20 married couples, chances are at least one or two fit the bill, or 5%, but estimates vary.
A sex educator for adults told me this was "free love, version 2.0." Most likely, these new monogamists are in the closet with their improvised arrangement. Sometimes, a happy marriage "opens up" because they want to do something more, or different. But in other cases, they do it because they want to maintain a functioning but emotionally inert marriage from the grips of divorce.
Still others reconcile the semi-happy marriage with a happy-happy life by having a more agnostic view of the romantic deal breaker of infidelity. They let extramarital affairs nick the consciousness of marriage, but don't discuss anything. They just decide to let the monogamy imperative drift.
These alternatives aren't for everyone, certainly. But it's worth trying to be imaginative if you want an alternative to divorce, and these are all arrangements that you'll find among couples today, however traditional they may appear.
Before you conclude that your only options are divorce or a life of eternal semi-happiness, imagine other options. Forever is a long time. It pays to be flexible.