Looks like the rivalry between Katy Perry and Taylor Swift had just become more interesting.

The country, now full-fledged pop star had allegedly dissed Katy in her new song "Bad Blood". And now... is Katy dating one of her exes for revenge?

Oooh looks like Tay and Katycat are both not ready to "Shake It Off"!

The "Roar" singer was spotted leaving LA hotspot Nobu last Sept 8, minutes after Harry Styles was also photographed on his way out.

In the photos published by Perez Hilton, Katy and Harry were unfortunately not snapped together. However, a source tells Hollywoodlife that the two we're actually getting cozy:

"Yes, Katy Perry and Harry Styles had dinner together at Nobu in Malibu late Thursday night. Just the two of them. They seemed happy, smiling and enjoying their dinner and conversation. They arrived separately and left separately. They looked like good friends and did a lot of talking."

Taylor and Harry dated in the fall of 2012 before splitting up last year. And the relationship probably did not end in good terms. Remember when she was caught dissing him during a Grammy performance not long after their break up?

Now how did the fight between the two started?

It was when Taylor revealed in an interview with Rolling Stone that a song of her upcoming album "1989", "Bad Blood", is about a "bad friend".

"She did something so horrible," Swift says. "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 day after the interview made headlines everywhere, Katy tweeted:

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

— KATY PERRY (@katyperry) September 9, 2014