Why do couples drift apart and separate? There are the usual suspects -- fights over money, infidelity, differing views on parenting -- and then there are the problems no one really talks about.
Below, marriage therapists share six of the most overlooked reasons couples get divorced -- and how to avoid them.
1. They never fight.
Don't worry about arguing, said Greg Cason, a Los Angeles-based psychologist. Worry when you no longer care enough to argue.
"The couple that never fights tends to slowly, but surely, drift apart until they have lost interest in the relationship," Cason told The Huffington Post. "The good news is that these breakups tend to be more amicable because the couple has slowly become more like friends than romantic partners."
The fix: If you're trying to avoid a split altogether -- amicable or otherwise -- Cason recommends speaking up when something doesn't sit well with you.
"Conflict is never welcome in a relationship, but it's often necessary to work out sticking points and help you move to new understanding with each other," he said.
2. They allow their in-laws to have a say in their marriage.
When you marry your partner, you marry their family. Unfortunately, sometimes you don't know how overbearing your in-laws will be until you've said "I do." The scenario becomes even more complicated when your spouse doesn't see a problem in their family's meddling, said Anne Crowley, an Austin, Texas-based psychologist.
"A husband may have trouble understanding why his wife has a problem with his parents' advice; as far as he's concerned, they're smart and give sound advice," she said. "But when couples are unable to manage their differing opinion, the strain on the relationship can become unbearable. They can turn on each other."
The fix: Be open to your in-laws' suggestions and assume they mean well, but ask your spouse to put your feelings first, Crowley said.
"Be a united front," she said. "Couples need to focus on championing their partners' views versus defending their parents. It's not about taking parents and in-laws out of the equation, it's about putting them on a different level."
3. They hold onto resentment.
Two years ago, one partner had an emotional affair with a co-worker. The couple has seemingly worked through the issue, but now, every time they fight, it's brought up again. That noxious pattern will continue until the wronged partner has truly let go of his resentment, Cason said.
"Holding onto past hurts only eats away at you and will motivate you to punish your partner when he or she least expects it," he explained. "You end up looking like the crazy one and eventually push your partner into greener pastures."
The fix: Move past your resentment before it's too late, Cason said.
"Take an inventory of your past hurts and work on truly forgiving your partner," he said. "Individual and couples counseling can really help with this one."
4. There's a lack of presence when they're with each other.
Nothing is as lonely as being in the same room with your spouse but never truly connecting. That feeling of being together but separate often drives couples to divorce, said Andrea Wachter, a marriage and family therapist in Northern California.
"The truth is, connecting is more than simply being in the same house, room or restaurant, though that's a good start," she said.
The fix: If you're still invested in your relationship, make a point to show it, Wachter said. Make eye contact when you're talking (yes, that means putting down your smartphone), schedule date nights and genuinely listen when your spouse tells you about his or her day.
"Even if it's just for a few minutes, try putting down your pad, phone or remote control on a regular basis and really take the time to connect with your partner," she said.
5. They're two very different people.
The old adage that opposites attract is true, but only up to a point, said Amanda Deverich, a marriage and family therapist based in Williamsburg, Virginia. Deverich used the example of a high-energy extrovert in love with a quiet introvert to illustrate her point.
"The more quiet, low energy person may be anxious and worn out by their partner's social life, but won't speak up and take time to recharge," she said. "Meanwhile, the other partner withdraws and becomes wary of venturing a solution because it will never meet their partner's standards."
The fix: If you and your spouse have different personality types, give each other permission to handle things in your own way, Deverich said.
"Don't challenge," she said. "Instead collaborate to find the best solution."
6. They don't know how to negotiate time apart.
When your spouse heads off on a business trip, you're suppose to miss him, right? But if you don't, it's easy to assume that the passion has fizzled out of the marriage, Crowley said. I don't miss my partner when they're away, so maybe I should be on my own? the thinking goes.
"People often mistake this sentiment -- or the lack of sentiment -- for not being 'in love' with the partner but it just means you are appreciating having your own space, where you can take a break from recognizing and incorporating someone else's needs. But some people experience this and think, 'it might be easier to break up and be alone. Then, I won't have to consider anyone's space but my own.'"
How to work on it: Recognize that needing or embracing time apart doesn't mean you're better off getting a divorce. In fact, spending time without your spouse every so often might make your marriage stronger than ever before, Crowley said.
"Part of the relationship puzzle is finding the right balance between closeness and separation," she said. "Sometimes, it's nice to have some time away to recharge and return to the relationship. Don't take it personally, just negotiate time apart."