"It went on for hours and hours," Sali, who is bisexual, is describing the time she says she was raped by a straight couple.

"There's a lot of it I don't remember but I remember the pain," she's certain her sexuality was part of the motivation.

Research from the US suggests that compared with straight or lesbian women, bisexual women are more likely to have experienced sexual violence in their lifetime.

Separately, the United Nations Human Rights Council describes lesbian and bisexual women as being "especially at risk" of being victims of sexual violence.

According to official figures, 0.7% of the UK's population identify as bisexual.

Warning: This article contains details of an alleged rape which you may find upsetting

Sali's story is one of those featured in Radio 1 Newsbeat's latest documentary Battling To Be Bi - which explores the struggles bisexual people face.

The film also follows a campaign for the UK's first major pride event specifically for bisexual people.

Media playback is unsupported on your device Media caption Battling to be Bi - a Newsbeat documentary

Sali says many of her memories of the alleged sexual assault took weeks to come back to her.

"They were just giving me loads to drink and I was drinking water because I'd had enough," she says. "But I kept finding vodka in front of me, not water."

Sali says in the build-up to the attack the couple repeatedly asked lots of questions about her sexuality - something she initially didn't find strange because of her work as a bisexual rights activist.

"When I stood up to go to bed they stood up as well and they grabbed me and that's when it started," she explains.

Image caption Sali says bi women are seen as "greedy, slutty, asking for it"

"I remember bits of it - like being smacked so hard around the head that everything went white and I couldn't see.

"I was there for maybe six hours in total and the only reason they let me out in the end was because they had work to do.

"So I went home, then passed out for a bit, and when I woke up I went to A&E."

Despite the violence, it wasn't until later that Sali started to consider what had happened as rape.

"Bisexuality is seen by a lot of people as just a type of porn with two women and one man and that definitely influenced what happened to me."

Image copyright Getty Images Image caption The bisexual pride flag has three colours - pink, purple and blue

Sali says she didn't go to the police because she feels she wouldn't have been successful in court.

Only around 2% of reported rapes in England and Wales result in conviction.

"Although I fully support people who do go to the police about sexual violence... bi women are seen as greedy, slutty, asking for it.

"So if I'd even had got as far as it having made it to court - which wouldn't happen anyway because it would've been dropped long before that - there's no way I'd win."

Geri Burnikell, from the rape charity SupportLine, said she would encourage all victims of rape to report it to police.

She added: "We fully understand that some are reluctant to do so due to the low conviction rates which means many perpetrators get away with what they have done."

If you've been affected by any of the issues discussed in this article, you can find help at the BBC Advice pages.

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