The Coronation Street actress, who plays barmaid Tina McIntyre, has won 'Sexiest Female' at the British Soap Awards for the last four years in a row.
"I am very flattered but I find it strange because I'm not a sexy person," she told the Daily Star. "I'm quite a tomboy really.
"Today I'm wearing jeans, Converse trainers and a hoodie and that's my normal everyday outfit."
Keegan went on: "As for photoshoots, I cannot do sultry and I can't pout. It literally looks like I'm in pain when I try to do a sultry face.
"That's why I'm normally smiling in every picture, I cannot do a sexy face. I can't do anything like it. It just doesn't look right!"
The 24-year-old added candidly: "My style is quite neutral. I hardly ever wear anything raunchy and I don't feel particularly comfortable getting my chest out.
"My body is quite small and my chest is either a 32DD or a 30E, so it makes me look boobie and I hate that. Even my character doesn't usually wear anything low-cut."