The Disney star sat down with her "Spring Breakers" cast for a Q&A about their upcoming flick at the South by Southwest festival in Austin, Texas.
When the girls were asked if they lip synced Britney Spears' "Baby One More Time" in the movie, they decided then and there that they would show fans the vocals in the flick were completely theirs.
Selena -- who's obviously the singer of the group -- had the best voice out of Ashley Benson and Rachel Korine, who were also on hand from the "Spring Breakers" cast.
Gomez even wowed Britney Spears who posted on Facebook, "Awww Selena Gomez can duet with me anytime! PS- I heard Spring Breakers is AAA-MAZING! Can't wait to see it!"