Pop star Taylor Swift is talking about One Direction's Harry Styles' former girlfriend Kendall Jenner in a line in her new single "Shake It Off," a source told Hollywood Life.

"She has a line that is very specific to Harry. When she talks about her ex bringing his new girlfriend that's Harry and Kendall," the source said.

Apparently, the source is referring to the part of "Shake It Off" when Swift raps, "My ex man brought his new girlfriend. She's like, 'Oh, my gosh.' I'm just gonna shake."

"And to the fellas over there with the hella good hair, won't you come on over baby? We can shake, shake, shake," the 24-year-old pop star continues rapping.

"Shake It Off" was said to be about Swift's former boyfriends. 

In 2013, Swift also dissed Styles during her VMA Awards speech and her Grammy Awards performance. But even after breaking up with Styles, Swift remained close with the One Direction band even setting up Selena Gomez with Niall Horan.

Meanwhile, Swift was recently attributed to Elizabeth Arden Inc's biggest ever quarterly loss along with Justin Bieber.

With the Swift and Bieber brands of celebrity perfumes, the company's fourth-quarter sales fell 28.4 percent, Chicago Tribune reported.

Swift's Elizabeth Arden fragrance is called Wonderstruck while Bieber's is called The Key.

"While we anticipated some decline in sales in our celebrity brands, we didn't anticipate the extent of the decline we experienced," Elizabeth Arden Chairman and CEO Scott Beattie said during a conference call with analysts.

Beattie remarked he was surprised by the customers' lack of interest in smelling like youthful pop stars Swift and Bieber.

Prior to this loss, Swift and Bieber's Elizabeth Arden fragrances performed well in 2013 with The Key being the third-highest selling celebrity perfume with US$37-million in sales and Swift's Wonderstruck ranked sixth with US$27-million, according to Euromonitor as cited by Financial Post.