The three ages at which affairs are most likely – and how to stop them

A new book How To Be Unfaithful Without Getting Caught is shamelessly designed to tell its mostly male-readership how to cheat and lie with impunity. In it, the Barcelona-based “infidelity coach” Albert Arnaiz outlines 29, 39 and 49 as milestones for when one member of a couple may decide to risk it all and have a secret affair.

Ten years ago, I started a therapist matching platform called Welldoing. Many of the people who seek therapy through it are reeling from the shock of discovering that their partner, who once promised lifelong commitment, has chosen someone else above them. There is even an affair-specific term for it: the American psychologist Dennis Ortman dubbed the condition post-infidelity stress disorder. Similar to post-traumatic stress disorder, it occasions feelings of anger, stress and depression, frequent crying, flashbacks and nightmares.

For lovers, affairs bring heart-racing excitement and forbidden sex, as well as fear of discovery and guilt. But the real victim is the one whose partner has lied to them. So it’s a good idea to consider what drives people into illicit relationships, and what partners can do to affair-proof their relationship.

I asked Albertina Fisher, an experienced relationship and sex counsellor who is often consulted by couples following affairs, what she made of Arnaiz’s end-of-decades milestones. Diplomatically she said she knew of no such research – “in my clinical experience, people can have affairs at any age” – but she could see the logic behind them in that they roughly translated into the commonly-found triggers for affairs.

Danger zone one: 29 

Getting married or becoming a parent is one time when people may feel trapped, as “the carefree, fun shiny person they are with seems to have changed,” explains Fisher. “It’s quite normal, for example, for a father to feel pushed out. The couple has become three and that might act as a trigger for a father to have affairs.”

Affairs occur in one in five marriages, with 25 per cent of men and 18 per cent of women cheating on their partner at least once. Arnaiz may be a libertine but he recommends any person who fears their partner’s wandering instincts should focus on communication. “Not seeing, not understanding, not communicating are the mistakes – talking and starting to find solutions are the solutions,” he says.

“You need to be willing to talk about difficult things,” says the intimacy coach Nicola Foster. “Avoiding difficult conversations or conflict is not good or helpful. We probably fear having our head bitten off, but the better option is to aim to be transparent and open about our fears and insecurities.”

She quotes the late British-born psychologist Sue Johnson who is known for her work in the field of psychology on bonding, attachment and relationships. “She says a couple needs to be ARE – that is, accessible, responsive and engaged. You may be busy with children, or work or looking after elderly parents, but you need to keep checking in, staying connected.”

“Conversations about what’s OK are important – does a woman care if her partner looks at beautiful women on Instagram? Where do they stand on OnlyFans? There is no right or wrong, it’s what works for each couple, to prioritise happiness and comfort with each other.”

‘A different version of themselves’

“Very often the reason for embarking on an affair is not that they want a different person, they want to be a different person,” says Albertina Fisher. “They are looking for a different version of themselves and can find that more easily with someone else.”

Affairs can be an exit strategy – when someone either consciously or unconsciously knows their relationship has run its course. “It’s hard to end a marriage. So an affair is embarked on as a catalyst,” says Foster.

There is also the revenge affair. Sometimes this might be because of another affair. But, explains Fisher, it can also be “a way of expressing anger, acting out of something that can’t be talked about. Then there are people who have affairs, because they can. For a man it might be because his father cheated. If people have grown up around affairs it can legitimise it for them,” she tells me.

At the age of 29, when you might be dealing with a young family, it’s important to make time for each other, and not be entirely tied up in chores and childcare. As Foster says: “The person with the higher sexual needs can often feel pushed out at this point.” Therapists encourage date nights and weekends with grandparents to give couples time to build intimacy and just be together without family pressures.

Danger zone two: 39

Foster points out that singling out the age of 39 for heightened affair-danger could fit with the generation who had “played the field in their 20s, married in their early to mid-30s and, on the brink of turning 40, thought: ‘am I only having sex with that person for the rest of my life?’ Both men and women can feel stifled like that, and often there will be children involved.”

Foster notes that the modern workplace can be a place where opportunistic affairs blossom. “You might see this with one person in an ambitious job, and the other member of the couple is not working outside the home. The working one might also have a better chance for late nights and travel. These are tension points.”

As one friend, Penelope, now in her mid-50s, told me: “When my husband confessed that he’d had an affair I was completely floored. It didn’t seem to matter that the affair had finished months before. It was so hot and vivid in my head that I could hardly sleep. I began drinking heavily every night and started to fall apart, even though we were still living together, with children. I couldn’t trust him to even speak on the phone without having to know who, why, everything.” She ended up in therapy for nine months.

Penelope’s husband’s affair had – like many affairs – started in the workplace but reflecting upon it now, she sees that it was a much deeper-seated issue. “He told me he could talk to her about anything, but felt he could talk to me about nothing. It was so painful to hear, but eventually I realised there was some truth in it. We didn’t really talk to each other. I knew there were problems but I was too scared of what talking about them would lead to, so I would literally turn away from any serious conversation.”

At 39, focusing on ambitions and careers can leave your relationship starved of attention. Fisher’s advice at this point is to check in with each other more. How are you feeling? Does this relationship still feel good to you? “Think about supporting the personal growth of your partner. Outgrowing each other can be a strong motivator for an affair.”

Danger zone three: 49

“Reaching middle age or the menopause can feel like a loss that is hard to process. There may be a lack of sexual or emotional intimacy in the relationship. Or a sense of boredom, the feeling they have outgrown each other.” This could be at 49, or later into a person’s 50s.

At 49 it may not be sex that is driving the infidelity, but the steady diminution of attention and encouragement can make the feeling of intimacy less frequent. This comes at the same time as the menopause, when women may start to experience sexual problems.

Sex can suffer badly, and usually silently. “What tends to happen is that someone brings up sex a couple of times and the person who has higher sexual need feels they can’t do it again. They are both hyper aware of it, but it’s unspoken. It may not actually be sex that is missing, but touch, closeness, being seen as a sexual being,” says Foster. She doesn’t prescribe sexy underwear or positions, but new ways of communicating about touch. What you wanted at 25 is not necessarily what you want now. But you may benefit from simply doing something playful together, she offers.

‘Our relationship now is far, far stronger’

Penelope, who is now more than eight years past her husband’s affair, recalls that sex had fallen off a cliff, but following her therapy and months of intense talking with her deeply regretful husband, they started to re-connect, emotionally and sexually. 

Fisher says couples who fully process what has happened, usually with a therapist, and quite often also some couples counselling, can become stronger if they decide to carry on. And Penelope tells me she would agree: “I obviously wish I hadn’t had to go through this, but I also know that the relationship we have now is far, far stronger and more loving than it was before.”

Fisher’s advice for any age is to check in with each other more. She also thinks that sex is often not, contrary to belief, the major part of what a person may get from an affair. “A lot of what they are seeking is intimacy, that they feel they have lost in their current relationship.”

In recent years, more people have opened up to consensual non-monogamy and, speaking to Foster, she tells me couples should discuss what constitutes monogamy for them. “An affair is secret – that is what does the damage.”