Taylor Swift says she wrote the song "Bad Blood" about a fellow star, telling Rolling Stone, "We're just straight-up enemies"

Taylor Swift is a girls' girl — but not every girl's girl. Speaking about her upcoming album, 1989, in a new interview for the latest issue of Rolling Stone, the "Shake It Off" singer opened up about her many female friendships, as well as a lesser-known female rivalry with an unnamed fellow star.

The pop superstar — who counts Selena GomezLorde, Lena Dunham, Karlie Kloss, Dianna Agron, Hailee Steinfeld, and Sarah Hyland among her bevy of famous BFFs — is a stickler for sisterhood. But she has no problem fighting fire with fire if someone wrongs her. See more pics of Taylor and her celeb friends.

Exhibit A? "Bad Blood," a song from 1989 that was written about another, albeit unidentified, famous female artist.

"For years, I was never sure if we were friends or not. She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'" Swift, 24, told the mag. "[Then last year] she did something so horrible. I was like, 'Oh, we're just straight-up enemies.' And it wasn't even about a guy!"

She continued, being careful not to name names. "It had to do with business," Swift hinted. "She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me. And I'm surprisingly non-confrontational — you would not believe how much I hate conflict. So now I have to avoid her. It's awkward, and I don't like it."

That said, Swift is not afraid to speak (or sing) her mind on the subject. "Sometimes the lines in a song are lines you wish you could text-message somebody in real life. I would just be constantly writing all these zingers — like, 'Burn. That would really get her,'" the "22" songstress said. "And I know people are going to obsess over who it's about, because they think they have all my relationships mapped out. But there's a reason there are not any overt callouts in that song."

Swift has no desire to put the artist on blast, but she does want people to know that the song is not, like so many of her other tunes, about an ex-boyfriend. "I know people will make it this big girl-fight thing. But I just want people to know it's not about a guy," she explained. "You don't want to shade someone you used to date and make it seem like you hate him, when that's not the case."

Tell Us: Who do you think "Bad Blood" might be about?