Bisexuality is booming, with the number of people who bed men and women more than doubling, a study says.
Some 7.7 percent revealed they had bi romps in 2014, compared to 3.1 percent in 1990.
The stats follow the openness of Brit model Cara Delevingne and other celebrities about their bisexuality. In the same period the percentage of men who reported having had sex with at least one man rose from 4.5 percent to 8.2 percent.
And the number of women who said they had bedded at least one female leapt from 3.6 percent to 8.7 percent.
Meanwhile, acceptance of same-sex sexuality has increased among all generations, says the US study of 30,000 adults.
Levels were up from just 13 percent in 1990 to 49 percent in 2014.
Last year Delevingne, 23, said she felt more comfortable with women.
She said: “I’m done with boys, all they care about is their willies.” She spoke of her relationship with singer St. Vincent, 33, adding: “My sexuality isn’t a phase — I am who I am.”
Lesbian sexual experiences are more likely to occur when women are young, the researchers found, while youth doesn’t appear to be a factor for male gay sexual experiences.
In terms of attitudes towards same-sex relations, between 1973 and 1990, the percentage of adults who believed “sexual relations between two adults of the same sex is not wrong at all” rose only slightly, from 11 percent to 13 percent.
Since then, however, such acceptance rose to 49 percent in all adults and 63 percent of Millennials in 2014.
Study author Professor Jean Twenge, of San Diego State University, said: “These large shifts in both attitudes and behaviour occurred over just 25 years, suggesting rapid cultural change.”
Twenge said several social and media factors are driving this change, but broadly Americans appear to care less about social norms and more about their own wants.
She added: “These trends are another piece of evidence that American culture has become more individualistic and more focused on the self and on equality.
“Without the strict social rules common in the past, Americans now feel more free to have sexual experiences they desire.”
The findings were published in the journal Archives of Sexual Behaviour.