Credit: Video Still

As most Pretty Little Liars fans know by now, Ashley Benson (Hanna) is one of the stars of Spring Breakers, an edgy indie film about four girls on a spring break trip gone extra wild. Her co-stars include Selena Gomez and Vanessa Hudgens, and one of their more innocent exploits in the film is bursting into an impromptu version of Britney Spears' "...Baby One More Time."

At a recent panel about the film at SXSW, Ashley, Selena, and co-star Rachel Korine were egged into doing a live performance of the song, to prove it wasn't lip-synched in the film. What began as a few bars became a full on karaoke style sing-along, complete with background music and words projected on a big screen.

We think the gals did a pretty good job, given that they were ostensibly completely unprepared for the surprise performance. Check it out!

Credit: YouTube Photo: Spring Breakers: The Stars Sing "Baby One More Time" Live

Spring Breakers follows four college friends who decide to rob a fast food restaurant to pay for their wild spring break vacation. After being arrested for drugs at a party, the girls are bailed out by druglord Alien (James Franco), but their freedom comes at a price: the girls must do his dirty work. The movie hits theaters nationwide on March 22. Lucky fans in New York and Los Angeles will get to see the Harmony Korine film a week early on March 15.

Find Pretty Little Liars spoilers here.

Catch the next episode of Pretty Little Liars on Tuesday, March 12, 2013 at 8 p.m. ET/PT on ABC Family.