They haven't even filmed a scene together yet, but it appears two of the actresses on FOX's upcoming Scream Queens are already involved in a nasty feud with one another.

Lea Michele Dishes On New Role On 'Scream Queens'

Reportedly, Emma Roberts has become extremely upset with co- star Ariana Grande over a rumor, and it has caused some tension on the show's set.

"Emma and Ariana are already butting heads and they haven't even shot a scene together yet!" a source told Hollywood Life.

Reportedly, the feud began when Roberts heard a rumor that Grande was trying to ban cell phones on set, and she didn't take to the news very well.

"Emma heard that Ariana doesn't want anyone to have cell phones on set and the rumor really upset her," the source said. "She ended up losing it during a rehearsal, while heatedly telling a producer how upset she was. Her fiancé, Evan Peters, was there and had to try and calm her down, but she ended up storming off the set."

It is unclear how true the rumor actually is however, as Grande is currently on tour in the U.S. through April 14, with an international tour slated to begin immediately after for two more months, and it hasn't been confirmed that she's been able to squeeze in time at the Scream Queens set just yet.

The show is one of more highly-anticipated ones coming to TV this fall, coming from Glee and American Horror Story creator Ryan Murphy, and being touted as a "comedy/horror." In addition to his former AHS star Roberts, Murphy has tapped former Glee front-runner Lea Michele, in addition to other big names for the show's cast. Those names include Grande, Nick Jonas, Jamie Lee Curtis, Keke Palmer, Skyler Samuels, Abigail Breslin, Diego Boneta, Breezy Eslin, Oliver Hudson and Lucien Laviscount.

Scream Queens premieres this fall on Fox.