Demi Lovato got into such a huge fight with her mother over her arm tattoo she had to walk out.

The American star has around 12 inkings on her body, some of which she regrets. Last year she claimed she might get some removed when she is older, but that hasn't stopped the 20-year-old singer adding to her collection.

In November she had 12 birds tattooed on her lower right arm by Kat Von D, something her mother was horrified about when she first saw it.

"Um, more like a day or so," Demi told Heat magazine, when asked how long they didn't talk for. "I went over to my mom's and I had it bandaged up, which probably made it look bigger than it was, so she just thought I'd got a half sleeve or something! She didn't react well and I ended up leaving. It was pretty bad."

Demi sees permanent inkings as an art form, but no matter how hard she tries, her mother Dianna won't see her point of view. That said, Dianna doesn't mind quite so much when her daughter brands herself discreetly. The star's father Patrick also disapproves, but tackles his feelings in a different way.

"My mom and I got into a huge fight when I got the birds on my arms, just because she has a different perception of tattoos than my generation does," Demi explained. "And so it's hard to explain to her that it's like art for your skin and you don't have to draw it on every day. It's something that's meaningful. My mom and dad get so mad! When it's littler ones, my mom doesn't mind so much, but we got into a huge fight over this.

"My dad still, to this day, has not mentioned anything about my tattoo, which is pretty funny."

Demi enjoyed a great deal of success last year, appearing on the panel of the US X Factor. Simon Cowell is her co-judge and was thrilled with how well she did in her first season, so she is coming back for another round of shows.

The young star gets on well with the music mogul, with the pair teasing each other regularly. Although they are close, there are some things Demi draws the line at.

"At least $50 million," she replied, when asked how much it would take for her to get a tattoo of Simon's face. "Yeah, $50 million or $100 million."