Julia Roberts reveals why she joined Taylor Swift on stage

Since Taylor Swift kicked off her world tour she's been joined on stage by a rotation of leggy models, fellow singers and erm, Julia Roberts.

Yep, in our all-time favourite Tay Tay moment, the Hollywood actress got up on stage during the 25-year-old's gig in Santa Clara, California, in August.

Want to relive the moment? Of course you do. Check it below!

Now doing the rounds for New York Fashion Week (her first in 15 years), the 47-year-old reveals the reason for her impromptu stage invasion. She tells all in her interview above.

And it was unexpected, with Julia stating: "I would have washed my hair if it had been planned. I was wearing a ponytail, leggings, and tennis shoes."

However, during the interview with Extra, Julia remains remarkably tight lipped about those divorce rumours.

Earlier this week, numerous sources stated that she and husband Daniel Moder – whom she has three children with – were on the rocks due to arguments over money.

Well, we're calling it…break-up stress or not, Julia's fashion week look is on point #killingit