Speaking to Rolling Stone alongside Game of Thrones co-star and best friend Maisie Williams, Sophie explained, "everyone experiments.
"It's part of growing up. I love a soul, not a gender," she continued.
Sophie also described how her fiance, Joe Jonas, is her "person", even though she once believed she would never settle down with anyone.
"I was fully preparing myself to be single for the rest of my life," she continued. "I think once you've found the right person, you just know. I feel like I'm much older a soul than I am in age. I feel like I've lived enough life to know. I've met enough guys to know -- I’ve met enough girls to know. I don’t feel 22. I feel like 27, 28."