The 'Boys and Girls' singer – who has shot to fame in the past year with two number one UK singles and a top ten album – attended the famous Italia Conti stage school, in London, and although she only dated one boy while she was there she is convinced he wasn't attracted to girls.
She told InStyle magazine: "There was this one boy who I went out with for, like, a month.
"To be honest, most of the boys at Italia Conti were gay. I think that boy I went out with is actually gay now!"
The 18-year-old star recently revealed she was looking for a boyfriend but can never tell when guys are flirting with her or find her attractive.
She said: "I don't know, but when I go out now, boys just come up to ask me to get a picture - not to ask for my number! But I'm also rubbish at knowing if anyone is hitting on me. I'm just really friendly and think everyone is the same, so I never realise when someone is interested!"
Undercover.com.au