From body shaming to willful silences, there’s multiple verbal red flags that can spell doom for couples.
Experts say there are many things that should never come out of your mouth, even in the middle of a red-hot shouting match.
Now, an American psychologist reveals the single ‘toxic’ phrase that could permanently ruin your relationship.
Dr Mark Travers, who has degrees from Cornell University and the University of Colorado Boulder, said it’s the number one phrase that breaks up couples.
And if you hear it coming from your partner’s mouth, it may be a sign to get out of that relationship fast.
‘There’s one phrase I’ve seen come up in these exchanges that’s more damaging than you think,’ he said in a new piece for CNBC.
‘If you use this toxic phrase, your relationship is in trouble.’
According to the expert, the phrase is: ‘Why can’t you be more like [insert other person’s name]?’

An American psychologist reveals the single ‘toxic’ phrase that could ruin your relationship (file photo)
When your boyfriend, for example, has uttered it, they’ll be comparing you with their ex-girlfriend, their friend, their mother, or even a version of yourself from the past.
Dr Travers calls this the ‘death-by-comparison’ effect – as it’s an obvious indication that your relationship is in trouble or on its last legs.
‘At first glance, it might seem like a throwaway line or a sigh of frustration in the middle of an argument,’ he explains.
‘What couples fail to recognize is that the person named is actually irrelevant, whether it’s an ex, a best friend’s girlfriend, or even “how you used to be”.
‘The real message will always remain the same: “You’re not enough, and someone else – anyone else – could do a better job at being my partner”,’ he explains.
Hearing the phrase directed at you can have a damaging effect on your self-worth, even when the relationship has been ended.
‘Over time, this kind of comparison can give rise to irreparable insecurity issues,’ added Dr Travers, who is the lead psychologist at Awake Therapy in New York City.
‘Rather than feeling loved for who they are, the person on the receiving end will start questioning their worth and constantly wonder if they’re living up to expectations.’

The ‘death-by-comparison’ effect is an obvious indication that your relationship is in trouble or on its last legs (file photo)
He continues: ‘Relationships can’t thrive when we ask our partner to be someone they’re not.
‘Happiness can only be achieved when we communicate what we need clearly, without shame or comparison.
‘That’s why this phrase itself isn’t the real problem. It’s usually a symptom of a much deeper dysfunction: the fear of openly speaking up.’
According to the expert, people might hold back negative feelings in a relationship, which can make them mentally sweep them aside them until they eventually spill over, resulting in the dreaded phrase being uttered.
He explains: ‘These moments only pile up over time, until the day comes that they inexplicably blurt out something like, “Why can’t you be more like Sarah’s husband? He actually plans dates.”
‘It’s not necessarily that they want a different partner; it’s that they don’t feel safe enough to voice their needs plainly.
‘The more secure and emotionally close a person feels in their relationship, the more likely they are to communicate directly.’
Dr Travers says relationships most often ‘don’t fall apart overnight’ but ‘crumble under the weight of small missteps’, many of which take a verbal form.
According to another relationships expert, there are four phrases that are instant red flags. In a viral video, TikTok star Jeff Guenther, from Portland, Oregon, said three of them are ‘We are so different’, ‘We never fight’ and ‘It moved so fast’.
But the fourth one is a little more surprising – ‘The chemistry is so hot’.
Guenther explains: ‘When I ask what they love about the relationship and they say, “the chemistry is hot and the magnetism is so strong, it’s hard to explain.”
‘It’s great to have an electric spark, but if you can’t name anything specific about why you’re a good match, it’s a little suspicious.’
Meanwhile, MailOnline’s sex expert Tracey Cox says there are 18 things you should never say in a relationship, including ‘Why can’t you be more like…’