Very pretty women have gay male best friends because they can't trust straight men who will try to 'sexually exploit' them, a study has found.
Researchers also found the most attractive females were unpopular with other women.
Other, less attractive women felt threatened, or feared they would steal their boyfriends, researchers found.
Showbusiness beauties often have a 'GBF' [gay best friend], or two in the case of Liz Hurley.
She turned to Elton John and David Furnish for shoulders to cry on after splitting with her partner Steve Bing.
In fiction, examples abound, with perhaps the most famous example being the TV show Will and Grace.
The show depicts the friendship between best friends Will Truman, a gay lawyer played by Eric McCormack, and Grace Adler, played by Debra Messing, a straight interior designer.
Carrie Bradshaw played by Sarah Jessica Parker in Sex and the City also has a 'GBF'.
The study, by researchers at the University of Texas at Arlington, was in two parts.
The first asked 68 young women to be photographed in form-hugging clothes.
Their photos were then assessed by a panel who rated them on a scale of 1 to 10 for attractiveness.
Then these photos were shown to a group of 103 people comprising heterosexual men and women - who were asked how much they agreed with the statements, on a scale of 1 to 7.
The questions asked of the men how likely they would be to: seduce the woman; convince the woman to have sex with him; tell the woman what she wants to hear in order to have sex with her; and persuade her he is a good catch.
Women were asked how likely they would: feel threatened by the woman; compete with the woman for a mate; withhold information from the woman about potential mating opportunities; and divert the woman's attention away from a potential mate that the female participant herself is interested in.
Perhaps predictably, the men were more likely to deceive and want to bed the most attractive women.
The results, published in the journal Personality and Individual Differences "revealed that more attractive targets were more likely to be sexually deceived by straight men and competitively deceived by women."
In the second study, the initial 68 women were asked to create an ideal group of friends by allocating 'friend dollars' to individuals of different genders and sexual orientations.
They found that "more attractive women allocated more dollars to gay male friends".
They were also asked what they valued in gay male friendships.
Among the reasons for valuing gay male friendships were impartial advice on relationships and clothes.
The researchers, led by Professor Eric Russell, said it showed a 'perception that gay men would value them beyond sex'.
In conclusion, the authors say that their findings show "attractive women are more likely to be sexually exploited and competitively deceived by straight men and other straight women" and "straight women's physical attractiveness is systematically linked to their desire for gay male friendships."
"Taken together these findings provide converging support for the idea that the women's own level of physical attractiveness play an important role in their willingness to form friendships with gay men."
They add: "These findings suggest that befriending gay men may be an important feature of women's mating strategies, especially among attractive women who face greater mating threats from heterosexual individuals."