Hayley Williams is decoding how she and Taylor Swift met.

The Paramore frontwoman, who will open for Swift on the next leg of her hugely successful Eras Tour, recalled how the "Bejeweled" singer's mom, Andrea, first connected them more than a decade ago.

"Me and Taylor met because both of us — Paramore and Taylor — were nominated for Best New Artist the same year at the Grammys," Williams told host Jimmy Fallon on Thursday's episode of The Tonight Show, referring to when both artists got nods in the category in 2008 alongside Feist, Ledisi, and Amy Winehouse. (The latter ended up taking home the award.)

Williams recalled, "We were at some Grammy party — it was actually Timbaland's Grammy party. Huge. I was very nervous, but a woman came up to me and she said, 'I'm Taylor Swift's mom and, you know, Taylor doesn't have a lot of friends her age that do music. And I would love to, like, you know, introduce you guys or get your number.'"

"I love Taylor's mom!" Fallon interjected.

To which Williams replied, "Andrea, the legend that she is. She connected us."

Fallon then presented a photo of the pals that featured Swift smiling and Williams excitedly giving a thumbs-up. "Every photo of us, one or both of us is like," said Williams, giving the camera a huge grin and a thumbs-up. "I don't know why!"

"That's your thing!" Fallon said.

Williams confirmed, "It is our thing. It's just to show how cool we are."

In the years since the Grammys party, Swift and Paramore have teamed up for several musical endeavors, including to perform the band's hit "That's What You Get" on Swift's Speak Now tour in 2011. Twelve years later, the group played on the opening night of Swift's Eras Tour and was featured on her previously unreleased "from the vault" track "Castles Crumbling," from the re-recorded version of her album Speak Now.

"Since Speak Now was all about my songwriting, I decided to go to the artists who I feel influenced me most powerfully as a lyricist at that time and ask them to sing on the album," Swift wrote on social media at the time. "They're so cool and generous for agreeing to support my version."

Listen to Williams recount the origins of her friendship with Swift in the clip above.

Sign up for Entertainment Weekly's free daily newsletter to get breaking TV news, exclusive first looks, recaps, reviews, interviews with your favorite stars, and more.

Related content: