Katy Perry Says She'd Collaborate with Taylor Swift ... "If She Apologizes"

After years of subtweets and thinly-veiled references to their longstanding battle, the "Rise" singer confirmed on Twitter over the weekend that, indeed, the two are very much on the outs.

While killing time waiting for her Cheesecake Factory delivery to arrive, Perry started responding to fans' questions on her Twitter page. While most were fairly innocuous, one really stood out: "Would you ever collab with Taylor Swift?"

Her answer: "if she says sorry, sure!"

In case you forgot, Swift's "Bad Blood" was rumored to be about Katy.

Taylor herself admitted the single was about another female artist, telling Rolling Stone in 2014, "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 added the other singer really crossed the line. "She did something so horrible. I was like, 'Oh, we're just straight-up enemies.' And it wasn't even about a guy! It had to do with business. 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."

The story goes that Perry allegedly tried to hire back some of Swift's dancers, leading most to assume the song is about her.