Katy Perry Sings Along to ‘Bad Blood’ With \201cOld Friend\201d Taylor Swift in Sydney

When it comes to Taylor Swift and Katy Perry, there used to be "bad blood" but now it's just "mad love."

On Friday, Feb. 23, the "Roar" singer posted a slew of photos to Instagram of her attending Swift's history-making "Eras Tour" in Sydney, Australia.

Along with a selfie of Perry and Swift posing together, the "E.T" singer posted a video of her singing along to "You Belong with Me" alongside Rita Ora, a snapshot of her midriff-bearing concert ensemble, and another video of her singing along to the infamous 2014 hit "Bad Blood."

"Got to see an old friend shine tonight ♥️✨" Perry captioned the post—an ode to Swift and her "Eras Tour" performance.

In a 2014 Rolling Stone profile, Swift discussed the female artist she sings about in "Bad Blood."

For years, I was never sure if we were friends or not," she told the publication at the time and without naming any names.

"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?'" Then last year, the other star crossed a line. "She did something so horrible," Swift continued. "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."

At the time, Crushable and others online pointed to Perry, who seemingly confirmed she was Swift's "enemy" after she she tweeted Watch out for the Regina George in sheep's clothing."

In 2018, the alleged feud between the two pop singers seemed to come to an end, after Swift posted anInstagram story of a note addressed to an "old friend."

Swift captioned the post with a simple, "Thank you Katy" and a double-heart emoji.

"Hey old friend—I’ve been doing some thinking on past miscommunications and feelings between us and wanted to clear the air," the note said. Fans could also se the words "deeply sorry."

In 2019, the pair also worked together for Swift's "You Need to Calm Down" music video.

“Katy agreed to do the music video because both she and Taylor are on the same page in regard to LGBTQ rights,” a source told Entertainment Tonight at the time. “They have both been big activists and feel very passionately about the cause.

“The video features RuPaul‘s Drag Race queens and many LGBTQ icons,” the source continued. “That is why Katy agreed to do the video and put their issues behind them because she felt it was for a good cause that she cares about.”