It looks like Taylor Swift is determined to keep her feud with Katy Perry going strong. The singer was reportedly not happy when she heard that her go-to production designer, Baz Halpin, has been asked to work with Perry on her upcoming Super Bowl Half Show. She is said to have demanded that Halpin, who has worked with both artists on recent tours, pass up the opportunity – or else she will refuse to hire him in the future.  

RadarOnline spoke with an entertainment insider, who pointed out, “Baz did Taylor’s most recent RED tour and the Speak Now tour, and he did California Dreamz and the current Prism tour for Katy.” While Halpin’s loyalty to both artists may have worked out fine in the past, it seems Swift has put her foot down when it comes to this game changing event. The source says, “She got word of Baz agreeing to do the show for Katy and Taylor’s flat out said she will not hire him ever again for any performance or tour if he goes ahead with his decision.”

The insider says that Halpin is very unlikely to adhere to Swift’s wishes on this, pointing out, “It’s obviously a huge career highlight for him and he wouldn’t pass up to chance to do it.” The source adds that he would “be nuts not to do the gig.”

Apparently, Perry isn’t too worried that Halpin will pass up this epic opportunity either.  The source says, “Katy got word of Taylor’s ‘Ultimatum’ and found it quite amusing.”

The rift between Perry and Swift appears to have been going on for years, but only became public in recent months. While promoting here upcoming album, 1989 Swift revealed in an interview that one of it’s songs, “Bad Blood,” is about her “straight up enemy” in the industry.  Many speculated that she was talking about Perry – a hypothesis that was only strengthened when Perry took to Twitter immediately following the release of the interview, writing, “Watch out for the Regina George in sheep’s clothing.”