"It can be really confusing," she tells news.com.au.
Her story is one of several in a new documentary Ms Davidson is directing called Handbag: the untold story of the fag hag. She has just raised $41,000 the film, ready for release next year.
She says she is not sure what she feels about the term "fag hag". It has a derogatory air, as such she prefers "handbag". But both refer to the same thing - straight women who have strong, often highly intense and mutually supportive, relationships with gay men.
These days, straight woman and gay men who get along would probably just be called mates, but "handbags" were often vocal and visual supports of the homosexual community when discrimination - legal and otherwise - was still rampant.
"So many women have acted as protectors, cheerleaders and supporters of their gay friends, but always in the background," Ms Davidson says.
"Straight allies, and particularly women, are a vital part of the fight for gay rights. That includes the current debates in Australia, such as marriage equality."
She says she is a "third-generation handbag". Her grandmother was a "beard", or fake girlfriend, to gay men she was close to; while her mother helped when the community was being devastated by AIDS.
"I'd been raised in a family with lots of gay men in it so I should have known better than anyone (not to fall in love with one)," Ms Davidson says.
"A gay man wasn't a shiny unicorn I'd never seen before. I'd been going to parties with drag queens when I was six, but it happens - hormones are crazy."
It was when she was at university, in her early 20s, that he walked into a class and before long she was smitten. Ms Davidson has said he would prefer not to name the man.
"He was smart, funny, good looking. We would stay up all night talking about films and he was flirtatious with me; at the movies he would put his arm around me.
"I wasn't sure if he was my boyfriend but I was the happiest I'd ever been. He was different to other guys, he spoke to me like I was a person."
The signs were there though. Something pretty key wasn't happening.
"We were both like 'hello cutie pie', let's go to the movies and dance, but I had horizontal shenanigans in mind and he, clearly, did not.
"I blame George Michael. I thought George was the most divine thing in my entire life and he was everything I wanted in a boy. The '80s were tough (for straight women) - Wham, Elton John, for god's sake."
Eventually things came to a head. "There was an incident when I went on an actual date and he got very jealous, he was confused," she says.
"So I drank to give myself Dutch courage and I said 'I'm in love with you, do you love me or not, what's the story?'
"And then he broke my heart into a million billion pieces. I was gutted."
Despite the heartache, Ms Davidson says she got off lightly.
"I know a woman who was in a relationship for 17 years before he came out as gay. I feel blessed mine was relatively short term."
Most of the time a gay best friend might be oblivious if his female friend has fallen for him. But some gay men actually encourage it, she says.
"One guy told me that, in a way, he used one of his female best friends in college. He was trying out being straight so picked the most gorgeous woman, everything he could want, and if that didn't work then, he thought, well I must not be interested in the whole gender.
"The coming out process is hard and sometimes people get hurt along the way," she says.
She says there was always a contradiction that lay at the heart of her relationship.
"He was all the things a young woman wanted - charming, funny and attentive - but not threatening precisely because, in the end, there was nothing romantic.
"For young women, that's important; it's a scary world out there dealing with blokes, we've seen that from 'Me Too' that so many young women have spent half their life being objectified.
"The wonderful thing about gay men is they talk to me like I'm a person because they don't want to get in your knickers."
The experience was life changing for Ms Davidson's ex as well. "Within a couple of months he was hitting the gay bars. He seemed to have a boyfriend within moments.
Annoyingly, he was lovely and we got along which was a bit of pain; I wanted to hate him," she laughs.
They instead remained friends, the pair are still in touch, but admits things were never the same.
"Is it healthy staying friends? I don't know, it hasn't worked out terribly well for some women (in the same position) but from a positive point of view, it's the embodiment of unconditional love."
Ms Davidson says straight men could learn a thing or two from their gay brothers.
"He gave me the guidebook of what to look for in a man. My husband is charming, funny and intelligent but, as he's straight, he wants to do horizontal shenanigans."
When she looks back, how does she feel about that intense brush with heartbreakingly raw unrequited love?
"I kind of knew (he was gay) and I kind of didn't. Denial is wonderful place when you're young," she says.
But she's learned a lesson. "I'm going to try not to fall in love with any more gay men."
The documentary Handbag is due for release in 2018.
