Social media has been lighting up with excitement over what many believe to be concrete proof that the two pop queens will be performing a song together.
On Tuesday, Dec. 6, an Xtina fan posted a screen shot from music-licensing website APRA that listed both Britney and Christina as performers on Brit's "Do You Wanna Come Over?," a song from her ninth studio album, "Glory."
German dance duo La Bouche are also listed as performers on the track.
"Here's a conversation starter. Not sure what this means but it certainly made me say WTF?! What are you up to @Xtina?," a user who goes by @TheChristinaVIP said.
Fans went absolutely crazy and started salivating at the potential duet.
"IVE BEEN WAITING 19 YEARS FOR THIS," one Twitter user wrote. Another said, "If this Britney and Christina collab is a lie I'm fighting everyone idc."
One enthusiastically said, "OMFG I love both of them!! ❤ Please let this be true!!! 🙏 Godney & Godtina together!"
The two former "Mickey Mouse Club" stars broke into mainstream consciousness around the same time in the late 90s. Many pitted them against each other since they were the around the same age, both did pop music and both followed a similar path to stardom.
The two worked together in 2003 when they performed with Madonna at the MTV Video Music Awards.
Over the years, media outlets have called the two "rivals," but in 2012, Xtina praised Brit when she was asked about the reality TV show "The X Factor" -- which Britney was a coach on at one point. "X Factor" competed against "The Voice," where Christina is commonly a coach.
"[We were in the] Mickey Mouse Club. We were very close, and our paths have always crossed and, interestingly, they will continue to cross," Christina told reporters. "I welcome her to this family of fun and entertainment and finding new talent as well. ... I don't know what [advice] she's going to offer specifically, but I know she's a pro. ... I think she's going to give great advice."