Gillian Anderson "never" identified with being gay "100 per cent".
The 43-year-old actress – who revealed to Out Magazine in March that she's previously been in relationships with women – admits she "always knew" she still liked men during her younger years, but she wanted to see what it was like to choose to experiment with the same sex.
She said: "I was talking to Out about gays and choice, and the view that you can just choose not to be gay in some way. I decided to talk about it now because someone with whom I was in a relationship a couple of decades ago – a woman – passed away about a year ago.
"I was talking about her and, in the context of the gentle conversation we were having, I thought I would say that I have had a couple of relationships with women, but that wasn't my experience because I did have a choice. I always knew I still liked boys.
"Being gay was never something that I identified with 100 per cent, because I knew that for me it wasn't the only way."
Gillian – who is a patron and fundraiser of the Trevor Project, a hotline which helps teens who are confused about their sexuality – believes it is an important time to speak up about her lesbian romances because there isn't a similar "fear" to be had with talking about same-sex relations as there was in the past.
She added to the Sunday Times magazine: "I haven't spoken up about it before because there isn't the same fear and stigma now that there was. But she had just passed and I just wanted to speak about it in a matter-of-fact kind of way."