Julia Roberts on her unplanned Taylor Swift tour appearance: 'I would have washed my hair'

Julia Roberts is still a pretty woman -- even if she hasn't washed her hair.

Extra spoke with the actress at the Givenchy show during New York Fashion Week, and the star revealed how she ended up on stage with Taylor Swift.

Roberts said she took her three children to meet Swift, when the singer asked her to appear during the show.

Taylor Swift's 1989 Tour: See All of Her Guests!

"Oh my god, I would have washed my hair if it had been planned. I was, like, wearing a ponytail and leggings, I mean, tennis shoes," Roberts explained.

"[Taylor] was sweet enough to ask me before the show. She was very sweet with my children who had never been to a show before, they are all big fans," Roberts added. "And she said, 'would you mind coming on stage during the song and dancing?' and I said to my children, 'Well, what do you think?' And they all said, 'Oh, Mom you have to do it!' and my youngest son said, 'Only do it if you want to, Mommy.' it was so sweet!"

See photos of Taylor's 1989 tour:

"It was just one of those crazy, out of body moments," Roberts said.

Roberts was also joined on stage by singer Joan Baez.

Watch the full Extra interview here.

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