Most people are aware of the big, obvious threats to a long-term relationship, such as cheating, lying or addictions—but there are more subtle ways that a marriage can be slowly killed off.

Jean-Claude Chalmet, a couples and family therapist of 30 years’ experience, has seen couples reach a point of no return without the pair ever having a moment of high drama: the relationship has been gradually poisoned by behaviors that have become habitual. “A romantic relationship that remains joyful, rewarding—and lasts—requires effort, compromise and resilience,” he says. “Negotiating the inevitable challenges and frustrations of long-term marriage in ways that protect and respect the bond requires skill—and emotional maturity.”

Here, he explains the corrosive habits that can be fatal for relationships—and how to change them before it’s too late. Long relationships, he says, can not only be revived but be given a new and exciting lease of life.

1.
Contempt and Mockery

Contempt is one of the biggest indicators to me that a couple are on a road to a split. It’s a way of making a partner feel worthless. Classic signs are sarcasm, mocking or eye-rolling as a standard response to whatever your partner says or does. The implication is that the other person isn’t worth listening to. So even if they’re saying something that you could be interested in, you don’t hear it. The other person can feel that their only option is to harden themselves too. This concentrated drip of toxicity inevitably erodes a relationship.

In my practice I ask the contemptuous partner what made them feel justified in behaving in this way. Do they believe they’ve been slighted or mistreated? Contempt is a passive, bitter way of punishing someone even if you think it’s “banter.” If you have got into this habit, I’d ask yourself: “Is this who and how you want to be? Is this how you want to be experienced?” Once they’ve been made aware of what it’s doing to the other person, whether they continue to use contempt becomes a conscious choice. If they’re willing to explore and explain why they do it, it is possible to save the relationship. You both need to be prepared to hear each other. This is, in my experience, a difficult conversation—but tough conversations can save relationships.

2.
Criticism and Disapproval

Saying “I don’t like it when you do this, but would this be OK instead?” isn’t criticism, it’s telling someone how you feel. Criticism is the harsh expression of disapproval. What endangers your relationship is the kind of nagging criticism that isn’t trying to fix a problem, but that’s just a little cruel. I know very few people who know how to do “constructive criticism” and it’s always subjective in a relationship. What people are critical about often relates to their own insecurities. What’s often really happening is that they are putting the other person down to feel better about themselves.

My advice is to record your partner in full critic mode—and play it back to them. You might say: “Is this really what you meant to say to me?” I’ve suggested this to couples. While a few clients try to justify it, most are aghast—they had no idea of how they were communicating. This tactic works. I ask: “If someone spoke like this to you, what would you do?” A lot of these behaviors are learned in childhood—perhaps they had a critical parent—and sometimes we need to use bold techniques to break habits.

3.
Silent Treatment, Stonewalling and Sulking

The silent treatment is usually a technique for dealing with the silent person’s own anger. Obviously, however, it deadens communication. It might seem that you are avoiding a big row and being a martyr by walking away—but you’re inflicting cold punishment. Stonewalling might be your way of coping with disagreement, but silence never resolves anything. So unless that’s your goal, I’d suggest that couples agree that when the stonewaller comes out of it, you talk. If one partner has said something really hurtful, you need to communicate that or it won’t change. Change requires difficult conversations—which nobody likes, but they’re better than remaining stuck in an unhealthy situation.

I’d advise the person receiving the silent treatment to address it directly but calmly, without inferring blame. “You’re not interacting with me, you’re not responding—why? You don’t have to talk to me right now but at least tell me why you’re not talking to me.” Or, “Do you want to remain this way, or do you want to talk about it and move on?” You can tackle anything head on—but watch your tone. Because it’s the tone that sets the mood of the discussion. I’d remind the stonewaller that these are choices. Think “who do I want to be?” You want the other person to be understanding, open up, apologize, start the conversation—but what are you willing to do?

4.
Belittling

If you lack confidence in a relationship, one way of fighting back is to belittle your partner. It’s being dismissive of their importance. I’m afraid that this is a form of bullying and, if left unchecked, will cause your relationship to die a slow and horrible death. If we want to stop a behavior, bringing it to awareness puts us halfway there. To do this assertively rather than aggressively, you might say: “I don’t like it when you speak to me like that—but I don’t think you’re always aware you’re doing it.” Avoid shaming or blaming, for your relationship’s sake.

Then—because with a habit like belittling, if we want to change things we must examine the root cause—you could add: “Where did you learn that?” Often, it’s from their family. I find that most people don’t want to be like the parent who made them feel small. Having a conversation about that can create more understanding between you. So many divorces happen because people don’t feel emotionally safe. The ability to tell your partner how you feel is the first step to recovering that security.

5.
There’s No Emotional Trust

Many couples in my clinic don’t trust each other. It’s not that they suspect infidelity, but rather they can’t be confident that their partner is on their side. They don’t feel emotionally secure with that person. So they might withdraw as a way of protecting themselves. Or, because they are sad or hurt about not feeling valued by their partner, they often become passive-aggressive. They don’t say that they’re sad or hurt but they want to make their partner feel as bad as they feel—often as a way of gaining back some control.

Passive aggression often has a sadistic element that damages the marriage. It can cause relationship death by a thousand cuts unless one partner is prepared to shift perspective. I say to all my couples: “Can you give the other person the benefit of the doubt?” It’s far better for the relationship if you can openly admit that you’re hurt, but also to start from the assumption that your partner didn’t intend to hurt you. That act of generosity means that the other person is more likely to be willing to listen and be cautiously receptive. Rebuilding trust is a gradual process.

6.
Poor Communication — You Can’t Seem to Get Through to One Another

A lot of couples come to my clinic saying: “We don’t communicate.” That might mean that they expect their partner to read their mind and instinctively know what they want or feel. Or it might mean that they’re scared of arguing, or asserting themselves. It almost always means they aren’t having sex. But of course you can’t have a close relationship when you’re unable to be your real self. I tell my couples that they always have a right to say how they feel, as long as they can do so without being cruel.

However, what often prevents people from being honest is fear that their partner will react unkindly or angrily. They’re protecting themselves, but at the expense of the relationship. What can stop the tailspin is if one person admits how they feel, for example: “I felt rejected when you said X.” It’s brave because by revealing their true emotion, they risk further rejection. But this is an opportunity for their partner, rather than reacting defensively (“I didn’t say X!”) to match that courage by responding warmly, and showing interest in how their partner feels. “I didn’t realize you felt that way,” they might say. “Tell me more.” I’ve seen this melt couples’ defenses because both are revealing that they care about each other.

7.
Lack of Regular Physical Contact

When people no longer feel emotionally safe, physical contact is the first casualty because they don’t allow themselves to be vulnerable. There’s no sex, because often one partner makes it clear they’re not interested, but the other is usually sensitive about rejection, so they stop asking. But more potently, any show of affection dwindles away—no hugs, no kisses, no stroke of the arm—because if your partner has flinched away once, you won’t risk that humiliation twice.

But I’ve seen often that couples care deeply, but they’re frozen and don’t know how to stop the rot. It’s frightening to make a conciliatory move when your partner feels like an adversary, but better to speak out rather than suffer silently, or try to guess what they’re thinking. “Is it something I’ve done that you don’t like?”

I advise saying anything that shows you want to be close. After months of mutual silence, one client told her husband: “I do want sex, but I’ve felt low.” He replied: “I think about it every day.” Crucially, neither was making a demand, just a small step towards each other. If casual physical contact has dwindled, it just takes one hand to reach across the sofa. Take a risk to be vulnerable. I’ve seen many couples who were consulting lawyers, but are still together and thriving, because they dared to express their needs.

8.
Lack of Appreciation or Gratitude

Often couples can’t wait to complain about what the other doesn’t do. There aren’t enough little thoughtful gestures! My friend’s husband brings her a cup of tea every morning! My cousin’s wife always buys his favorite cheese! But people express love differently, and one person might express theirs by providing the family with a stable income.

It’s important to appreciate what your partner does contribute, even if you feel that you need the little thoughtful gestures. I see so many couples where there’s little capacity for gratitude, which creates a lot of negative feeling. It makes people feel that they can never be good enough. In this situation, I’d encourage you to consider what you should be thankful for, and express that. Gratitude begets goodwill, and even if it’s not natural for your partner to express their love in the way you crave, if they feel valued, they might be more willing to try.

9.
Never Accepting Blame

It’s immature to be unable to accept responsibility. If you or your partner can’t accept blame when at fault, and are allergic to saying sorry, it’s hard to heal rifts—it’s also dishonest and insulting. Increasingly, I see people who can’t cope with the smallest criticism—they haven’t learned to regulate their emotions. If their relationship is to last, they need to.

My advice, when people say, “My husband or wife won’t accept blame,” is to prompt them to ask their partner: “Is there any part of this that you’re willing to take responsibility for?” If the answer is “No” then we have a serious problem. But I suggest that you don’t demand an immediate answer or apology. Let them reflect—maybe for an hour, or a day. You might say: “I’ll leave it with you, we can talk about this again tomorrow.” By then, people are more likely to realize that saying sorry might not be good for their ego, but it’s good for the relationship. And when the relationship is better, you both feel better.

Anna Maxted is a London-based journalist and novelist