Britney and Madonna Back on the Road Together? Britney and Madonna Back on the Road Together? Los Angeles (E! Online) – Remember when Britney Spears just showed up at Madonna's L.A. tour stop and sorta comatose-jiggled through a halfassed duet of "Human Nature"? Well, it's payback time! We're hearing from inside musical spies that Madonna's planning on paying back her crazy little showbiz sis, Brit-Brit, and showing up at one of her upcoming concerts—too fierce and fab! What could the duet possibly be they'd choose from Britney's eclectic song catalog? Their already existing job together, "Me Against the Music," would just be too insanely appropriate, and since both babes are far more into the shock factor than actually making beautiful music together, scratch that notion. Instead, we're told a far more likely choice would be something along the lines of… ..."Womanizer," Britney's current brilliant and subversive comeback number; love it. "Although it's Britney's trademark song right now, don't for sure count on her sharing it with Madonna," we're advised by Spears insiders. Also, don't get too used to the notion of anything being totally duet-official right now; it's all in the early stages, and Madonna's camp is certainly being cautious at this point. "I don't see this happening," Madonna's lioness gatekeeper, Liz Rosenberg, exclusively tells us. "Madonna is still on tour, but I'll let you know." Hmmm, how interesting. First off, Liz likes to say things aren't true, emphatically so, when they are, e.g., Madonna was never going to get divorced. Second, the sort of brush-off entirely means Madonna just might do it; trust me on this. That is, if Ms. M. can steal herself away from that dude she's so busying trying to have another kid with, A-Rod. Oh, and did L.R. just accidentally confirm the rumor that Madonna might extend her current tour, which is scheduled to stop as of Dec. 21 in São Paulo, Brazil? The talk that Queen Madge is extending into Asia after that would surely seem all the more likely since Liz said Madonna's going to be busy touring during Brit's own tour, which doesn't even start till March 3, right? Right.