Did Katy Perry Confirm Taylor Swift's 'Bad Blood' Song Is About Her?

If you're going to insult Katy Perry, expect some serious shade in return.

A quick primer: Yesterday, Taylor Swift's Rolling Stone profile found her discussing a new song off 1989 called "Bad Blood," which is about an unnamed female celebrity who was, you know, "Mean," and also professionally screwed her over. The Internet quickly decided said anonymous artist was Perry -- some of Swift's dancers left her tour to go to Perry's, they've both dated John Mayer, and other 'evidence' points.

Who Does Taylor Swift Have 'Bad Blood' With? Five Guesses

Instead of saying nothing and letting the silly speculation continue (Perhaps forever! We still don't know for sure who "Dear John" is about!), Perry went on the offensive with this beautifully shady tweet posted Tuesday morning: 

Watch out for the Regina George in sheep's clothing...

— KATY PERRY (@katyperry) September 9, 2014

To borrow some parlance from Oprah, here's what we now know for sure:

1) Never mess with someone who knows how to deploy a perfect Mean Girls reference.

2) OMG, even Perry agrees that song is probably about her. 

3) Between the above tweet and her own shady Rolling Stone profile opener, Perry's got more shade than a giant umbrella at the pool.  

4) If this, and this, and this, and a zillion other examples didn't already convince you, in a hypothetical world where you know Swift, you do not cross her.

5) Hearing all the lyrics to "Bad Blood" for the first time is going to be the best lyrical experience this side of "Don't you think nineteen's too young to be messed with / The girl in the dress cried the whole way home."