The reality TV star, 25, said she questioned whether or not she was even attracted to women as she struggled to get past kissing her ex girlfriend - despite her being "attractive" and "funny".
In a chat with The Sun's Fabulous magazine, Megan admitted their relationship had "no substance".
She told the publication: "Demi's attractive, beautiful, she's a funny person, but there was no substance between us.
"It even got to a point where I was doubting myself, like 'do I like women?' We would just kiss, I couldn't do anything more. I felt I liked her more as a friend. I'd be laying in bed with her and all we could do was kiss.
"We couldn't get past that point and I was doubting if I'm actually gay. It's not right. She's a lovely girl but we didn't have that spark."
Megan reportedly started dating Demi, 22, when they filmed E4's Celebs Go Dating. The pair were later spotted cuddling at ITV's wild summer party.
It even got to a point where I was doubting myself, like 'do I like women?'
She told the newspaper she would like to settle down with a woman because she has a "deeper connection" with the same sex.
The reality star explained that she first fell in love with a girl when she was 16 but not "in a sexual way".
Megan rose to fame on the 2018 series of Love Island. She got to the final with Wes Nelson and the pair dated for several months after leaving the villa, finally parting ways during Wes's stint on Dancing On Ice.
She is currently dating 27-year-old professional footballer Chelcee Grimes, who is also a successful singer-songwriter - having written tracks for the likes of The Saturdays, Kesha and Kylie Minogue.
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