Ms Moran, 37, told PinkNews that she had not previously had same-sex relationships and was “surprised” to find herself attracted to a woman, but added: “Sometimes, when you meet the right person, it just kind of happens.”
She said she was more comfortable with the label “pansexual” than “bisexual” or “gay” because it referred to the idea of love for an individual person for who they are and not their gender or sexual identity.
The Oxford West and Abingdon MP said she had been “shocked” by people in public life who suggested her relationship with former Lib Dem head of press Rosy Cobb could damage her career, and made clear she would take it into account when deciding whether to stand in the forthcoming race to succeed Jo Swinson as leader.
She is regarded as the most serious rival to acting leader Ed Davey, expected to make a second bid to head the party after missing out to Swinson last year. Moran considered joining last year’s contest, but her putative bid was scuppered when it emerged she had been arrested after an altercation with her then boyfriend at a Lib Dem gathering in 2013.
Asked if she will stand this time around, Ms Moran said: “It’s a really big decision to make, and it’s one that I haven’t made yet.
“But I do know that you bring your friends and family and all of you with you when you decide to do something like that, so it’s not something I’m going to be doing or saying lightly.”
Ms Moran said parliament was “weird and backward” in its attitudes towards LGBT+ people, compared with society in general.
While her family and friends were supportive, she said that coming out as a pansexual MP had been more difficult.
“When it became more widely known that we were together, I was quite shocked, actually,” she said. “There were a few people who said ‘How serious is this?’ and some people even overtly said ‘Don’t you think it would be better for your career if you weren’t together?’
“They definitely would not have said anything like that had she been a man.”
While politicians like Justine Greening and Ruth Davidson had provided “brilliant role models” after coming out as lesbian, it was not clear whether any other MPs would identify as pansexual or bisexual, Ms Moran said.
“Within that Westminster bubble, I’m not going to lie, doing this is a bit ‘Ooh, what are people going to think?’
“But I don’t really care, because I know that in wider society it’s more than just fine. It’s something that we now all accept.”
Ms Moran said that all of her previous romantic attractions had been to men and she found it “surprising” when she began a relationship with her female partner, who she met at work, about six months ago.
“We just totally hit it off, started hanging out, and one day after a couple glasses of wine…” she said. “It was really wonderful on the one hand, but also quite surprising for me in how I had identified before.
“It wasn’t really something I had done before or considered before, but sometimes, when you meet the right person, it just kind of happens.
“We’re in a really committed, loving, supportive, relationship, and I feel now is the time to talk about it, because as an MP I spend a lot of my time defending our community and talking about our community. I want people to know I am part of our community as well.”
Explaining the word she uses to describe her sexual identity, Ms Moran said: “Pansexuality, to me, means it doesn’t matter about the physical attributions of the person you fall in love with, it’s about the person themselves.
“It doesn’t if they’re a man or a woman or gender non-conforming, it doesn’t matter if they identify as gay or not. In the end, these are all things that don’t matter – the thing that matters is the person, and that you love the person.”
She revealed that she has discussed her relationship with former party leader Tim Farron, a committed Christian who famously sparked controversy during the 2017 general election campaign by suggesting he personally regarded gay sex as sinful.
“I haven’t said the word pansexual, but he does know about my relationship and he’s really supportive,” she said