Hilary Duff says she was extremely scared of 'mean' co-star on this notable teen movie

Hilary Duff has opened up about a fellow cast member in a film who got so in character they made her feel 'scared' during filming.

The star, 38, spoke about the movie that she starred in when she was just 15 years old in an interview with Variety.

Duff, who is known for her role as Lizzie McGuire, revealed that her co-star had gotten so much into character that she had to constantly remind herself that it was just a scene they were acting out together.

She explained that the part that she was playing had a relationship with Duff's character that meant being mean was a part of the role.

It's easy to forget just how straight up weird acting can be as a job - after all, you may have just met someone and then an hour later you're both weeping over your dead mother or exchanging barbed comments as mortal enemies, and that's only compounded when you're still young!

Duff opened up about filming A Cinderella Story (Bruce Glikas/WireImage/Getty)

In Duff's case, it was Jennifer Coolidge, who played Duff's wicked stepmother in A Cinderella Story, filmed when Duff was just 15 years old.

Duff revealed that she has been interested to watch the career of Coolidge since then, saying: “It’s been so much fun to watch her career because she just goes there in such a big way that it was really impressive and slightly intimidating as like a teenager."

The star explained: “She was, like, mean to me, so it was a little scary ’cause I was only 15 and she was just, you know, mean to me cause she’s my evil stepmother.

“At the time, I think I had to be like, ‘You’re filming a movie. You’re filming a movie.'”

That must have been very convincing then!

Coolidge has since gone on to have success on The White Lotus, and Duff says she's been 'obsessed' with her.

Jennifer Coolidge played Duff's evil stepmom in the film (Mike Marsland/WireImage/Getty)

“I can’t even begin to tell you how much I’ve just been, like, obsessed with this past year for Jennifer Coolidge," Duff revealed. "It’s been really cool to see."

She also recalled another memorable moment in which Coolidge's character engaged in an unusual beauty regimen involving raw salmon.

“My favorite moment was her rubbing salmon on her face while filming A Cinderella Story and talking about the omegas,” Duff said.

“My son actually started eating sushi when he was like 3 and had a similar moment, and I looked and I was like, ‘You’re just rubbing raw salmon on your face.’

"And it’s, like, soft and he liked it, then it reminded me of her. She’s just everything.”