But she's opening up about it again and we love her for it.
Speaking to InStyle magazine, she has dubbed herself as sexually "fluid."
"I'm very fluid, and I think love is love. You can find it in any gender. I like the freedom of being able to flirt with whoever I want."
Demi touched on the topic in her recent documentary, Simply Complicated, saying that "I am open to human connection, so whether that's through a male or female, it doesn't matter to me."
But back in September 2017, Demi received some backlash for refusing to give a straight answer when Pride Source asked her directly. At the time, it was when she was spotted holding hands with rumoured girlfriend Lauren "KITTENS" Abedini.
She explained, "I just feel like everyone’s always looking for a headline and they always want their magazine or TV show or whatever to be the one to break what my sexuality is. I feel like it’s irrelevant to what my music is all about. I stand up for the things that I believe in and the things that I’m passionate about, but I like to keep my personal life as private as possible when it comes to dating and sexuality and all that stuff just because it has nothing to do with my music. Unfortunately, we live in a world where everyone is trying to get that soundbite and I am purposefully not giving the soundbite."