Kelly Clarkson bans her children from watching From Justin to Kelly

Kelly Clarkson has banned her children from watching her 2003 movie From Justin to Kelly.

The Since U Been Gone singer, who has been open about her disdain for the film, has revealed that she won't let her children, River Rose, 12, and Remy, 10, watch the musical comedy.

During her last Las Vegas concert on Saturday, Kelly spotted a fan wearing a T-shirt inspired by the movie, and stated that she was "contractually obligated" to star in it alongside runner-up Justin Guarini after winning the first season of American Idol in 2002.

"Man, read the f**king fine print, you know," the pop star joked, according to Us Weekly. "I didn't know that if you won, you had to do a movie. Not all of us want to be Meryl Streep, we just like watching her, OK? I was like, 'I don't want to be in a movie,' but they were like, 'Yeah, but you won.' And I was like, 'And I feel like I'm losing? It doesn't feel quite like a win.'"

The 44-year-old confessed that she cried over the "hard" experience because acting was "not what (she) wanted to do", however, she enjoyed "the music part" and working with music producer/songwriter Tommy Sims.

She added that she has no intention of letting River Rose and Remy watch the film, which follows a waitress and college student who meet during spring break in Florida.

"It is funny though, like, my kids, I've banned them from watching," she revealed. "My nanny's, like, 'I loved that movie when it came out.' I was like, 'And I judge you - all day, all night.' I'm just kidding."

Kelly made her movie debut in the 2002 independent film Issues 101. Since From Justin to Kelly, which was a critical and commercial failure, she has only had voice acting roles in animated films such as Trolls World Tour, UglyDolls and The Star.

The singer shares her children with her late ex-husband Brandon Blackstock.