Having fewer conversations is a top sign your relationship is failing

This was followed by preferring to scroll through phones rather than talk to one another and retreating to separate rooms to watch TV.

A survey of 2,000 adults found other key warnings included no longer doing fun activities together, sleeping separately, and not making an effort with date nights.

Among those who admitted to staying in a romantic relationship longer than necessary, 63 per cent did so because they hoped things would improve, while 33 per cent were afraid of change.

But this tendency to stay loyal to things that simply aren't delivering anymore extends beyond relationships and into possessions.

Nearly (47 per cent) have owned a microwave for longer than they were in a romantic relationship and, 36 per cent admitted to holding onto one even though it was no longer performing well.

The research was commissioned by SharkNinja, which also partnered with Olivia Attwood, who opened up about her own relationships, both with people and appliances, that have lost their spark.

To highlight this inertia across the board, Attwood has posted a tongue-in-cheek film on her socials that begins like a heartfelt break-up conversation – before revealing that she's in fact addressing her microwave.

Olivia Attwood said: "The fact that so many people have owned a microwave for longer than a relationship shows just how attached we become to things we're familiar with.

"As much as I see the value in holding onto things that have served us for long periods of time, it’s so important to upgrade certain elements of our lives."

The study found microwave owners expressed similar reasons for staying put as they do in relationships.

Among those hanging onto an old appliance, 59 per cent said it was because it still worked and 36 per cent had just not got around to replacing it.

But this leads to many people continuing to put up with common frustrations, such as unevenly cooked meals (16 per cent), slow cooking times (15 per cent), and crispy food losing its crunch (13 per cent).

It also emerged many struggle to let go of all sorts of things long past their useful life, such as old chargers and cables (52 per cent).

Along with clothes that no longer fit (52 per cent), dated receipts and paperwork (46 per cent), and birthday cards and handwritten notes (43 per cent).

Appliances can also become a surprising source of conflict during break-ups, as 13 per cent have argued with an ex-partner about who would keep household items.

Televisions (43 per cent), gaming consoles (29 per cent), and microwaves (27 per cent) were among the most disputed possessions.

Meanwhile, 19 per cent admitted they had kept an appliance following a split mainly because they did not want their ex-partner to have it.

Carolyn Anderson, from SharkNinja UK, which is marking the launch of its Ninja CRISPi Microwave, said: "There's something very British about putting up with something because it technically still works, even when we know it could be delivering much better results."