Taylor Swift is reportedly none too pleased that fellow country starlet Kacey Musgraves stole the show at Grammy Awards last month.

"Taylor has been telling pals she feels threatened by Kacey," a source says. "Taylor can't stand her, and she wants to be the only breakout young country star, but now with Kacey in the game, that title is in jeopardy." Such rumors are nothing new for Swift. Around the time of the 2013 Grammy Awards, Swift allegedly hated Carrie Underwood so much that Grammy executives made sure to prevent them from even crossing one another's paths at the ceremony.