The Katy Perry/Taylor Swift feud just got totally out of control!

It's common knowledge that T-Swift and Katy Perry are not the best of buds, but things have been relatively calm between the pair for the last couple of months.

Now though, it seems the feud has gotten out of hand once again.

In a seriously catty move, Katy's reported boyfriend Diplo took to Twitter yesterday to rant about Taylor's lack of "booty." 

Katy Perry has apparently been seeing the DJ for the last couple of months, and she's definitely got him on her side, if this latest development is anything to go by!

Things are getting personal!

Diplo then took things one step further and actually set up a crowd-funding account to raise money for Tay-Tay's bum… which attracted 17 supporters and a sum total of $45. We somehow doubt Taylor will be taking the money!

Back in September, Taylor opened up to Rolling Stone about her ongoing bad blood with the Friday Night singer – though she didn't specifically call Katy out. "For years, I was never sure if we were friends or not,” she said in the interview, discussing an unnamed star.

“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?'”

Taylor also admitted that the mystery star had "done something so horrible" to do with "business." It's thought that Katy poached some dancers from Taylor's crew to use on her own tour.

Well, we had hoped the two could patch things up but after this latest diss we aren't so sure!