London - It is something that many wives and girlfriends have long suspected.
Lots of men find "bromances" – close friendships with other men – more emotionally rewarding than their romantic relationships with women.
Whether it is the lure of going to the pub, a football match, fishing or just helping a pal with DIY, a best mate can leave many women feeling they play second fiddle.
Now British researchers looking into close male friendship among heterosexual men may have an answer. They found men felt "less judged" by their close male friends than their girlfriends. They also found it easier to solve conflicts and speak openly about their emotions in bromances.
However, the authors of the study warn these relationships could threaten the traditional patterns of men and women living together.
The report said: "Because heterosexual sex is now achievable without the need for romantic commitment… the bromance could increasingly become recognised as a genuine lifestyle relationship; whereby two heterosexual men can live together and experience all the benefits of a traditional heterosexual relationship."
Male friendships used to be considered lacking in many of the qualities seen in close female friendships – particularly emotional and physical intimacy.
But this has changed in recent years, the study found, as young men "openly pronounce love" to their male friends in a way that would have been socially unacceptable in the past – partly out of fear of appearing gay.
The author of the study, Adam White of Winchester University, interviewed 30 British male undergraduates for the study published in the journal Men and Masculinities. Of the men, 28 out of 30 said they would rather discuss important emotional issues with their "bromantic" partner than their girlfriends.
One study participant, "Brad", said: "There are absolutely things I tell my bromances and not the girlfriend. She expects so much from the relationship and will have a go if I say something out of line, and with Matt we just tell each other everything."
Summarising the research, Mr White said: "Our participants mostly determined that a bromance offered them elevated emotional stability, enhanced emotional disclosure, social fulfilment, and better conflict resolution, compared to the emotional lives they shared with girlfriends."
The research said other reports have found ‘men in their 30s have regrets about not maintaining their bromances into later life, with marriage being a key barrier to this.
Up to the early 20th century, men would often write "endearing letters" to one another, and even sleep in the same beds. For four years, for example, President Abraham Lincoln shared a bed with his male friend, Joshua Speed.
Such behaviour started to disappear amid a rise in homophobia. This has reversed today, the authors say, with much more male interest in art, music and fashion. They compared the macho Rambo movie character to the band One Direction as an example of how male identity has changed in recent years.