There are some couples who’ve been together so long, you just can’t imagine them separating: Posh and Becks, Barack and Michelle Obama – or Bill and Melinda Gates, perhaps. 

But the Microsoft co-founder and his wife, the company’s former general manager, have announced they’re ending their marriage of 27 years.

“We have raised three incredible children and built a foundation that works all over the world to enable all people to lead healthy, productive lives,” the pair said in a joint statement. “We continue to share a belief in that mission and will continue our work together at the foundation, but no longer believer we can grow together as a couple in this next phase of our lives.”

The news got us thinking about long-term love – and why some couples decide to part ways, even after decades together. In later life, it’s rarely an explosive row or sudden infidelity that causes marriage breakdown, says relationship therapist Pam Custers, who’s a Counselling Directory member. Instead, it’s usually a slow realisation that you’re no longer on the same page.

Here are some common themes Custers hears among couples who are considering divorce. 

Longing for fulfilment 

The late 40s and 50s bring “the perfect storm” for many couples, Custers tells HuffPost UK. People this age become the “sandwich generation”, often caring for children and elderly parents simultaneously, which can put pressure on a relationship. At the same time, many become disillusioned with work, perhaps feeling disappointment if career goals haven’t been reached. 

At this age, growing pressure can mount to make lifestyle (or relationship) changes, before it’s too late. “People sometimes feel: ’I’ve got this window of opportunity that I can’t squander, because I’m getting older,” says Custers.

“Often, they feel they’ve got [a chance] to fulfil themselves, and they’re asking what that fulfilment means. Is it fulfilment in the relationship, or is it as odds with the relationship?”

Children leaving home

When children move out, the family dynamic shifts overnight and this can ramp up the longing for change. “Prior to children leaving home, parents are often very focused on children and their careers – there’s a lot of outside focus and demands on their attention,” Custers explains.

“Then, when children leave home, there’s a shift of identity and purpose and that brings questions of: what is the purpose of our marriage? Why are we together? What are the things we have that keep us together as a couple, other than our children?”

For some people – particularly women if they’ve shouldered childcare responsibilities – this can coincide with a desire to shake up the home routine.

“Couples are used to a certain rhythm of family life and that changes,” says Custers. “One small example I hear sometimes is that women who’ve cooked for 30 years and have made sure there’s a meal on the table for children suddenly say: ‘actually, I don’t want to do this anymore.’” 

Miscommunication during the menopause 

Children leaving home often coincides with the menopause, which brings its own physical and emotional challenges. “It’s a moment where the gears shift and that can also place pressures on a relationship,” says Custers.

“Libido can often flag, there can be physiological challenges on a woman at that stage. Men will often say: ‘I just don’t understand her anymore, who is this person I’m married to, because she’s completely changed?’”

Custers says menopause desperately needs to be normalised and embraced by both members of the couple, with frank conversations on everything from sex to sleeping with the window open during hot flushes. 

“If you make it an issue that can be navigated by both parties, it becomes something that’s doable for the relationship,” she says. “When it’s her problem and not his problem, it polarises.” 

Differing hopes for the future 

“Couples can grow apart, that’s the reality,” says Custers, adding that the pandemic has sped up the process for some. “Pre-pandemic, our lives were so busy. Our lives have work, sport, demands from a whole range of things… when you strip that away, a lot of couples have looked at each other and said: ‘Do we still hold the same values any more? Are we the same people?’”

Again, as work and childcare responsibilities begin to wind down, we have more space to think about what we want from the next stage in life. “Perhaps one member of the couple is thinking about a shift in gear in terms of how they want to live their lives, while the other still wants to do a lot with their lives,” she says. 

So, how can you navigate these challenges? 

Like most relationship challenges, the key to keeping on the same path is good communication. “This is a pivotal moment where couples need to recalibrate,” says Custers. ”They need to say: okay, this is a shift, this is a change, but how do we make this work for us?

“Just because there are different views or ideas, just because there’s a shift in the family dynamic, it’s about not being scared by that, but embracing it – because it can open up a whole lot of exciting conversations for a couple.

“If used well, it can be a moment where the relationship steps up a notch and shifts into something really lovely.”