The 'Baby One More Time' singer was being interviewed by US TV show Entertainment Tonight when the subject of her pregnant pal came up.
Britney and Zoe starred together in the movie Crossroads and, when asked if they'd ever act together again, Brit replied: "Who knows? That's a very good idea. But she's pregnant with twins right now so I'm sure she's got a huge future ahead of her."
Twins? Was that meant to be a secret?!
Avatar and Star Trek actress Zoe has been very tight-lipped about her pregnancy, not even officially confirming it until last month, way after her bump had actually begun to show.
The notoriously private star is married to artist Marco Perego.
Britney and Zoe were pictured together at Los Angeles International Airport earlier this week, shortly after Zoe had spoken fondly of her time acting with Britters in Crossroads.
Zoe had said: "I have a huge amount of respect for Britney Spears and I've always said this, and will always continue to say it, she was the one big, big celebrity that I met when I was starting to work in Hollywood who literally was humble."
"Whatever was going on in her mind and in her world, it was never about hating her neighbour… She had the biggest fan base and I do believe that people and children gravitate to good energy and she's definitely in abundance of that."
Britney then replied via tweet, saying: "Truly the sweetest, thx 4 the kind words. Nothing but great memories of working w u. Crossroads pt 2? ;)"
Stars who welcomed babies in 2014:
Copyright: Rex Features WENN/Matthew Taylor/Daniel Deme/Josiah True/Matthre Taylor/Joe
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