Mel B was in the bathroom when she helped write the Spice Girls' "Wannabe" in 1996.

The "Spice Up Your Life" star, born Melanie Brown, appeared on the Wednesday (May 14) episode of The Tonight Show Starring Jimmy Fallon, and revealed she was "on the loo," when she penned the lyrics to the band's best-selling song.

"You know I wrote the rap of that in the toilet. On the loo. 'Cause I'm like 'Girls, give me like a second to write a rap,' because I thought I was a rapper back then. Clearly not, but I was in my own world, and you know, I own it. In my version, it's a Leeds rap."

In the middle of the track, Scary Spice raps:

"So here's a story from A to Z/ You wanna get with me you better listen carefully/ We got Em in the place that likes it in your face/ You got G like MC who likes it on a/ Easy V doesn't come for free she's a real lady/ And as for me, ha you'll see."

She also wrote the line "I wanna really, really, really wanna zigazig ah," featured in the chorus, and, to this day, has not revealed what it means.

During a 2024 episode of Today with Hoda & Jenna, she explained that the mysterious lyric will forever remain a "group secret," per People.

Fellow Spice Girls Geri Halliwell (Ginger Spice), Emma Bunton (Baby Spice), Melanie "Mel C" Chisholm (Sporty Spice), and Victoria Beckham (Posh Spice) also contributed to writing the song.

The '90s icons reunited at Beckham's "posh" 50th birthday party in April 2024 and put on an impromptu performance for friends and family. They sang a few tracks, including 1997's "Stop," and football star David Beckham shared footage on Instagram.

Watch Scary Spice talk about where she wrote the rap to the Spice Girls' most popular track below!